Updated on 2024/02/15

写真a

 
SHIRAI Hiroshi
 
Organization
Faculty of Science and Engineering Professor
Other responsible organization
Electrical, Electronic, and Communication Engineering Course of Graduate School of Science and Engineering, Master's Program
Electrical Engineering and Information Systems Course of Graduate School of Science and Engineering, Doctoral Program
Contact information
The inquiry by e-mail is 《here
Profile
Dr. Hiroshi SHIRAI received the B.E. and the M.E. degrees in Electrical Engineering from Shizuoka University, Japan, in 1980 and 1982, respectively, and the Ph.D. degree from Polytechnic University (presently re-named as Tandon School of Engineering, New York University), New York in 1986. He was a Research Fellow, then a Postdoctoral Scientist until March 1987 in Polytechnic University. Since April 1987, he has been with Chuo University, Tokyo, Japan, where he is currently a Vice President, the Director of International Center and a Professor. He has been serving as a committee member of various technical societies and international meetings. He is now an Editorial Advisory member of IEICE Fundamentals Review. He received the R.W.P. King Best Paper Award from the Antennas and Propagation Society of the IEEE in 1987, IEICE Electronics Society Award in 2019, and IEICE Best Paper Award in 2020. His current research interests include wave propagation and diffraction in time harmonic and transient domains. Dr. Shirai is a Fellow of the IEICE and The Electromagnetic Academy, Senior member of the IEEE, and a member of Sigma Xi, the IEE of Japan.
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Degree

  • Ph.D. ( Polytechnic University )

  • Master of Engineering ( Shizuoka University )

  • Bachelor of Engineering ( Shizuoka University )

Education

  • 1986.6
     

    Polytechnic University   Graduate School, Division of Engineering   Course of Electrical Engineering   doctor course   completed

  • 1982.3
     

    Shizuoka University   Graduate School, Division of Engineering   Course of Electrical Engineering   master course   completed

  • 1980.3
     

    Shizuoka University   Faculty of Engineering   Department of Electrical Engineering   graduated

Research History

  • 2020.1 -  

    Chuo University   Vice President

  • 2018.4 -  

    Chuo University   International Center   Director

  • 2013.4 - 2015.10

    Chuo University   Faculty of Science and Engineering   Associate Dean

  • 2009.4 - 2013.3

    Chuo University   Admissions Center   Director

  • 2009.11 -  

    Chuo University   商議員

  • 2007.4 - 2009.3

    Chuo University   Korakuen IT Center   Director

  • 2007.4 - 2009.3

    Chuo University   Center for Information Technology and Computing Services   Vice Director

  • 1998.4 -  

    Chuo University   Faculty of Science and Engineering   Professor

  • 1988.4 - 1998.3

    Chuo University   Faculty of Science and Engineering   Associate Professor

  • 1988.4 - 1991.3

    Tokyo Denki University   Faculty of Engineering   Part-time Lecturer

  • 1987.4 - 1988.3

    Chuo University   Faculty of Science and Engineering   Lecturer

  • 1986.6 - 1987.3

    Polytechnic University   Division of Engineering   Post Doctoral Scientist

  • 1982.9 - 1986.6

    Polytechnic University   Division of Engineering   Research Fellow

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Professional Memberships

  • 1996年アンテナ伝播国際シンポジウム(ISAP96)

  • 1989年アンテナ伝播国際シンポジウム(ISAP89)

  • 1992年アンテナ伝播国際シンポジウム(ISAP92)

  • 1993 EMC/Tokyo

  • 2000年アンテナ伝播国際シンポジウム(ISAP2000)

  • 2001年電磁界理論の進歩に関する国際シンポジウム(PIERS2001)

  • 2007 IEEE Radio and Wireless Symposium

  • 2008 IEEE Radio and Wireless Symposium

  • Second International Conference on Communication and|rn|Electronics (HUT-ICCE2008)

  • 2009 IEEE Radio and Wireless Symposium

  • 2010 IEEE Radio and Wireless Symposium

  • The Third International Conferences on Communications|rn|and Electronics (ICCE2010)

  • 2010 Asia-Pacific Radio Science Conference|rn|(AP-RASC2010)

  • 2011 IEEE Radio and Wireless Symposium

  • Acoustical Society of Japan

  • The Institute of Electronics, Information and Communication Engineers (I)

  • Sigma Xi,The Scientific Research Society

  • ASA(Acoustical Society of America)

  • Institute of Electrical Engineers in Japan

  • Science Council of Japan.

  • The Institute of Electronics, |rn|Information and Communication Engineers

  • The Institute of Electronics, |rn|Information and Communication Engineers(II)

  • The Institute of Electronics, Information and Communication Engineers

  • IEEE (Institute of Electrical and Electronics Engineers)

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Research Interests

  • Electric engineering in general,Radiowave propagation,Antennas,Radio communication systems and equipment,Radar,Noise,EMC,Communication measurement general,Environmental Influence Accessment (including Radiobiology),Other environmental pollution

Research Areas

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Communication and network engineering  / Communication/Network engineering

Papers

  • High Frequency EM Scattering by a Large Building with Multiple Windows Reviewed

    C. M. Bui, H. Shirai

    C. M. Bui and Proc. of 24th edition of the International Conference on Electromagnetics in Advanced Applications (ICEAA 2023)   50   2023.10

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  • Extended Physical Optics Approximation for Edge Diffraction by Dielectric Wedges Reviewed

    D. M. Nguyen, H. Shirai

    Proc. of 24th edition of the International Conference on Electromagnetics in Advanced Applications (ICEAA 2023)   49   2023.10

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  • High Frequency Scattering by a Thick Conducting Plate With Multiple Holes -E Polarization Case-

    C. M. Bui, H. Shirai

    Proc. of URSI General Assembly and Scientific Symposium 2023 (URSI GASS 2023)   CDROM   2023.8

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  • TM Polarized Plane Wave Scattering by a Conducting Plate with Multiple Holes Reviewed

    Cuong Manh Bui, Hiroshi Shirai

    2023 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (USNC-URSI)   841 - 842   2023.7

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:IEEE  

    DOI: 10.1109/usnc-ursi52151.2023.10238017

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  • Uniform Asymptotic Solution for Edge Diffraction of H-Polarized Electromagnetic Plane Wave by Dilectric Wedges Reviewed

    D. M. Nguyen, H. Shirai

    D. M. Nguyen and H. Shirai, ``Uniform Asymptotic Solution for Edge Diffraction of H-Polarized ElectroProc. of URSI International Symposium on Electromagnetic Theory 2023 (URSI EMTS 2023)   CDROM   2023.5

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  • New Formulation of Physical Optics Approximation for Edge Diffraction by Dielectric Wedges Reviewed

    D. M. Nguyen, H. Shirai, S.-Y. Kim

    Proc. of 2022 International Conference on Electromagnetics in Advanced Applications (ICEAA 2022)   CDROM   2022.9

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  • Fundamental Analysis on EM Wave Scattering by Simple Cracks on Conducting Plane

    R. Sato, H.Shirai

    Proc. of 2022 Japan Radio Science Meeting (URSI-JRSM)   CDROM   2022.9

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  • Electromagnetic Wave Scattering Analysis by a Window Aperture on a Conducting Wall Reviewed

    Cuong M. Bui, Khanh N. Nguyen, Hiroshi Shirai

    Progress In Electromagnetics Research C   122   95 - 108   2022.8

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    High frequency electromagnetic plane wave scattering by a large rectangular glass window on a conducting wall has been analyzed in this study. Scattering far-fields are formulated by means of the Kirchhoff approximation in which the fields are obtained from radiation integrals due to the equivalent current sources on the virtually closed window apertures. In order to consider the effect of the window glass, a dielectric slab layer has been inserted in the window hole, and the reflection and transmission through the slab are treated via waveguide modal theory. The validity of our formulation has been confirmed by the numerical comparison with another method for an empty window case. The effects of the window dimension, the glass layer, and the polarization have been discussed for practical high frequency mobile communications.

    DOI: 10.2528/PIERC22041501

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  • TM Polarized Plane Wave Scattering by a Window on a Thick Conducting Wall Reviewed

    C. M. Bui, H. Shirai

    Proc. of 2022 IEEE International Symposium on Antennas and Propagation (APS/URSI 2022)   CDROM   2022.7

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  • A Discussion on Physical Optics Approximation for Edge Diffraction by A Conducting Wedge Reviewed

    D. M. Nguyen, H. Shirai

    IEICE Trans. Electron.   E105-C ( 5 )   176 - 183   2022.5

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    In this study, edge diffraction of an electromagnetic plane wave by two-dimensional conducting wedges has been analyzed by the physical optics (PO) method for both E and H polarizations. Non uniform and uniform asymptotic solutions of diffracted fields have been derived. A unified edge diffraction coefficient has also been derived with four cotangent functions from the conventional angle dependent coefficients. Numerical calculations have been made to compare the results with those by other methods, such as the exact solution and the uniform geometrical theory of diffraction (UTD). A good agreement has been observed to confirm the validity of our method.

    DOI: 10.1587/transele.2021ECP5031

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  • On the Asymptotic Evaluation of the Physical Optics Approximation for Plane Wave Scattering by Circular Conducting Cylinders Reviewed

    Ngoc Quang Ta, Hiroshi Shirai

    IEICE Trans. Electron.   E105-C ( 4 )   128 - 136   2022.4

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    In this paper, the scattering far-field from a circular electric conducting cylinder has been analyzed by physical optics (PO) approximation for both H and E polarizations. The evaluation of radiation integrations due to the PO current is conducted numerically and analytically. While non-uniform and uniform asymptotic solutions have been derived by the saddle point method, a separate approximation has been made for forward scattering direction. Comparisons among our approximation, direct numerical integration and exact solution results yield a good agreement for electrically large cylinders.

    DOI: 10.1587/transele.2021REP0001

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  • Uniform Asymptotic Solution for Dielectric Wedge Diffraction Based on Equivalent Currents Invited Reviewed

    D. M. Nguyen, H. Shirai, S.-Y. Kim

    Proc. of XXXIV General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS 2021)   CDROM   2021.8

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  • Extended Physical Optics Approximation for Electromagnetic Wave Scattering from Penetrable Objects Invited Reviewed

    Hiroshi Shirai

    Proc. of XXXIV General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS 2021)   CDROM   2021.8

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  • GO-Based Equivalent Current Formulation for Scattering from Circular Conducting Cylinders and Strips Reviewed

    N. Q. Ta, H. Shirai

    Proc. of 2021 International Conference on Electromagnetics and Advanced Applications (ICEAA 2021)   CDROM   2021.8

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  • Electromagnetic Scattering Analysis from a Rectangular Hole in a Thick Conducting Screen Reviewed

    K. N. Nguyen, H. Shirai, H. Serizawa

    IEICE Trans. on Electronics   E104-C ( 4 )   134 - 143   2021.4

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    Electromagnetic scattering of an electromagnetic plane wave from a rectangular hole in a thick conducting screen is solved using the Kirchhoff approximation (KA). The scattering fields can be derived as field radiations from equivalent magnetic current sources on the aperture of the hole. Some numerical results are compared with those by the Kobayashi potential (KP) method. The proposed method can be found to be efficient to solve the diffraction problem for high frequency regime.

    DOI: 10.1587/transele.2020REP0001

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  • Approximate analysis of EM wave scattering from two cracks on a ground plane Reviewed

    R. Sato, H. Shirai

    Proc. of 2020 ISAP International Symposium on Antennas and Propagation   CDROM   2021.1

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  • High Frequency Asymptotic Evaluation for Electromagnetic Scattering from a Circular Conducting Cylinder -E Polarization- Reviewed

    N. Q. Ta, H. Shirai

    Proc. of 2020 ICCE International Conference on Communications and Electronics   CDROM   2021.1

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  • TE Plane Wave Diffraction by Window Aperture on a Thick Conducting Wall Reviewed

    K. N. Nguyen, H. Shirai

    Proc. of 2020 IEEE International Conference on Advanced Tecnologies for Communications (ATC 2020)   CDROM   2020.10

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  • A Field Equivalence between Physical Optics and GO-Based Equivalent Current Methods for Scattering from Circular Conducting Cylinders Reviewed

    Ngoc Quang Ta, Hiroshi Shirai

    IEICE Trans. Electron.   E103 ( 9 )   382 - 387   2020.9

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    Plane wave scattering from a circular conducting cylinder and a circular conducting strip has been formulated by equivalent surface currents which are postulated from the scattering geometrical optics (GO) field. Thus derived radiation far fields are found to be the same as those formulated by a conventional physical optics (PO) approximation for both E and H polarizations.

    DOI: 10.1587/tranele.2019ECP5048

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  • High Frequency Diffraction by Thick Loaded Conducting Slits -H Polarization Case- Reviewed

    K. N. Nguyen, H. Shirai

    Proc. of 2020 IEEE International Symposium on Antennas and Propagation (APS/URSI 2020)   CDROM   CDROM   2020.7

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  • Uniform Asymptotic Solution For Conducting Wedge Diffraction Based On Physical Optics Current

    Minh Duc Nguyen, Hiroshi Shirai

    Prod. of IEICE General Conferenece   CDROM   2020.3

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  • Electromagnetic Education [I]: How Can We Realize Deep Understanding at Universities and Colleges Invited Reviewed

    A. Hirose, H. Shirai, A. Komiyama, N. Miyata

    Journal of IEICE   103 ( 1 )   68 - 73   2020.1

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  • Fundamental study on electromagnetic wave scattering from two cracks on conducting plane

    Ryoichi Sato, Hiroshi Shirai

    IEICE Technical Report on Electromagnetic Theory   EMT2019-49   261 - 264   2019.11

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  • High Frequency Asymptotic Evaluation of PO Integral for EM Scattering from PEC Circular Cylinder Reviewed

    T. Q. Ngoc, H. Shirai

    Proc. of 2019 International Conference on Electromagnetics and Advanced Applications (ICEAA 2019)   CDROM   2019.9

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  • Fundamental Analysis of Electromagnetic Wave Scattering from Multi-layered Window Glass in Multi-frequency Band Reviewed

    R. Sato, H. Shirai

    Proc. of 2019 International Conference on Electromagnetics and Advanced Applications (ICEAA 2019)   CDROM   2019.9

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  • High Frequency Diffraction by Rectangular Hole in a Thick Conducting Screen -H Polarization Case- Reviewed

    K. N. Nguyen, H. Shirai

    Proc. of 2019 PhotonIcs & Electromagnetics Research Symposium (PIERS 2019)   CDROM   2019.6

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  • Relationship between power density and surface temperature elevation for human skin exposure to electromagnetic waves with oblique incidence angle from 6 GHz to 1 THz Reviewed

    K. Li, K. Sasaki, S. Watanabe, H. Shirai

    Physics in Medicine and Biology   64 ( 6 )   Online - 065016   2019.3

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    This study presents an investigation of human skin exposure to obliquely incident electromagnetic waves at frequencies from 6 GHz to 1 THz. We aim to clarify the relationship between the power density and the skin surface temperature elevation under various exposure conditions. A Monte Carlo simulation was conducted to assess the transmittance and surface temperature elevation considering the variation of skin tissue thickness. For the case of TM wave injection, transmittance increases with increasing incidence angle from the normal incidence because of the Brewster effect. The normal incidence is confirmed as the worst-case exposure condition when the incident power density is defined in an area normal to the propagation direction.

    DOI: 10.1088/1361-6560/ab057a

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  • Kirchhoff Approximation Analysis of Plane Wave Scattering by Conducting Thick Slits Reviewed

    K. N. Nguyen, H. Shirai

    IEICE Trans. Electron.   E102-C ( 1 )   12 - 20   2019.1

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    Kirchhoff approximation (KA) method has been applied to analyze the plane wave scattering by conducting thick slits. The scattering fields can be considered as field radiations from equivalent magnetic current sources assumed by closing the aperture of the slit. The obtained results are compared with those of other methods to validate the accuracy of the proposed formulation in different conditions of slit dimension.

    DOI: 10.1587/transele.E102.C.21

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  • High Frequency Electromagnetic Scattering Analysis by Rectangular Cylinders -TM Polarization- Reviewed

    H. N. Quang, H. Shirai

    IEICE Trans. Electron.   E102-C ( 1 )   21 - 29   2019.1

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    In this study, transverse magnetic electromagnetic plane wave scatterings by rectangular cylinders have been analyzed by a high frequency asymptotic method. Scattering field can be generated by the equivalent electric and magnetic currents which are obtained approximately from the geometrical optics (GO) fields. Our formulation is found to be exactly the same with the physical optics (PO) for the conducting cylinders, and it can also be applicable for dielectric cylinders. Numerical calculations are made to compare the results with those by other methods, such as the geometrical theory of diffraction (GTD) and HFSS simulation. A good agreement has been observed to confirm the validity of our method.

    DOI: 10.1587/transele.E102.C.21

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  • High Frequency Scattering from Dielectric Rectangular Cylinders -TE Polarization-

    H. N. Quang, H. Shirai

    IEICE Technical Report on Electromagnetic Theory (EMT)   EMT2018-50   53 - 58   2018.11

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  • Plane Wave Diffraction by Loaded Slit in a Thick Conducting Screen

    K. N. Nguyen, H. Shirai

    IEICE Technical Report on Electromagnetic Theory (EMT)   EMT2018-52   65 - 70   2018.11

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  • Electromagnetic Plane Wave Diffraction by Thick Conducting Slits -E Polarization Case- Reviewed

    K. N. Nguyen, H. Shirai

    Proc. of 2018 International Symposium on Antennas and Propagation (ISAP 2018)   CDROM   2018.10

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  • EM Wave Scattering by a Window on a Wall Reviewed

    H. Shirai, M. Shimizu, R. Sato

    Proc. of 2018 International Conference on Electromagnetics and Advanced Applications   CDROM   2018.9

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  • Reflection and Transmission Features of Scattered Field from Multi-layered Window Glass in High Frequency Band Reviewed

    R. Sato, H. Shirai

    Proc. of Progress in Electromagnetics Research Symposium (PIERS 2018)   CDROM   2018.8

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  • H-polarized Plane Wave Diffraction by Thick Conducting Slits Reviewed

    K. N. Nguyen, H. Shirai

    Proc. of Progress in Electromagnetics Research Symposium (PIERS 2018)   CDROM - 436   2018.8

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  • Diffraction Study with Prof. Kohei Hongo Reviewed

    H. Shirai

    Proc. of Progress in Electromagnetics Research Symposium (PIERS 2018)   CDROM   2018.8

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  • High Frequency Scattering from Conducting Rectangular Cylinder via Surface Equivalence Theorem Reviewed

    H. N. Quang, H. Shirai

    Proc. of Progress in Electromagnetics Research Symposium (PIERS 2018)   CDROM   2018.8

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  • H-polarized Plane Wave Diffraction by Thick Conducting Slits Reviewed

    K. N. Nguyen, H. Shirai

    Proc. of Progress in Electromagnetics Research Symposium (PIERS 2018)   CDROM   2018.8

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  • A New Interpretation of Physical Optics Approximation from Surface Equivalence Theorem Reviewed

    H. N. Quang, H. Shirai

    IEICE Trans. Electron.   E101-C ( 8 )   664 - 670   2018.8

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    In this study, the electromagnetic scatterings from conducting bodies have been investigated via a surface equivalence theorem. When one formulates equivalent electric and magnetic currents from geometrical optics (GO) reflected field in the illuminated surface and GO incident field in the shadowed surface, it has been found that the asymptotically derived radiation fields are found to be the same as those formulated from physical optics (PO) approximation.

    DOI: 10.1587/transele.E101.C.664

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  • Plane Wave Scattering from Two Cracks on Conducting Plane Reviewed

    R. Sato, H. Shirai

    Proc. of Progress in Electromagnetics Research Symposium (PIERS 2018)   CDROM   2018.8

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  • High Frequency Wedge Diffraction Analysis via Surface Equivalence Theorem Reviewed

    H. N. Quang, H. Shirai

    Proc. of 2018 IEEE International Symposium on Antennas and Propagation (APS/URSI 2018)   CDROM   2018.7

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  • Proposal of Novel Reflection/Transmision Coefficient for Efficient Propagation Analysis at Outdoor-indoor Interface Environment Reviewed

    R. Sato, A. Takatori, H. Shirai

    Proc. of 2nd URSI AT-RASC   CDROM   2018.5

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  • A Compact Metamaterial Quad-band Antenna Based on Asymmetric E-CRLH Unit Cell Reviewed

    H. B. Chu, H. Shirai

    Progress In Electromagnetics Research C   81   171 - 179   2018.2

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    In this paper, a compact metamaterial quad-band antenna is presented. The antenna is designed from a unit cell of asymmetric extended-composite right/left handed transmission line (E- CRLH TL) as the main resonator part and a 50 Ω coplanar waveguide (CPW) as the feeding part. The design concept and resonant frequencies are analyzed and discussed. The results show that the proposed antenna exhibits four frequency bands covering GSM810, WLAN 2.45/5.5 GHz and WiMAX 3.5 GHz bands. The overall size of the fabricated antenna is only 57.2mm×31.2mm×1.6mm and is very small compared with other proposed quad-band antennas. In addition, a good agreement can be seen among the estimated resonant frequencies, HFSS simulated and measured results.

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  • Plane Wave Diffraction by a Rectangular Hole in a Thick Conducting Screen

    K. N. Nguyen, H. Shirai

    Technical Report on Electromagnetic Theory (EMT), IEICE   EMT2017-66   171 - 176   2017.11

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  • A Study on Reflection/transmission Characteristics by Multi-layered Dielectric Slab for Efficient Radio Wave Propagation Analysis

    R. Sato, H. Shirai

    IEICE Technical Report on Electromagnetic Theory (EMT)   EMT2017-64   149 - 152   2017.11

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  • High-frequency Asymptotic Solution of Scattering Field by Three-layered Dielectric Slab for Accurate Propagation Analysis Reviewed

    R. Sato, H. Shirai

    Proc. of 2017 International Symposium on Antennas and Propagation   CDROM   2017.10

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  • Electromagnetic Plane Wave Scattering by a Rectangular Hole in a Thick Conducting Screen Reviewed

    K. N. Nguyen, H. Shirai

    Proc. of 2017 International Conference on Electromagnetics and Advanced Applications   CDROM   2017.9

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  • High Frequency Plane Wave Scattering Analysis from Dielectric Cuboids - TM Polarization - Reviewed

    H. N. Quang, H. Shirai

    Proc. of 2017 URSI General Assembly and Scientific Symposium (GASS)   CDROM   2017.8

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  • Design of Multiband Antennas Using Asymmetric E-CRLH TL unit cells Reviewed

    H. B. Chu, H. Shirai

    Proc. of 2017 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting   2531 - 2532   2017.7

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  • Electromagnetic Scattering Analysis by a Window Model on a Building Wall Reviewed

    M. Shimizu, H. Shirai, R. Sato

    IEICE Trans. Electron.   J100 ( 7 )   295 - 301   2017.7

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    High frequency electromagnetic wave diffraction by a window and the window glasses have been analyzed. The problem has been modeled as two dimensional thick slit loaded with a dielectric material layer, and formulated by the Geometrical Theory of Diffraction and the ray-mode conversion technique. The validity of our formulation has been tested by comparing the results with these by the Kobayashi Potential method for relatively narrow slit aperture cases. Then the various numerical calculation results have been made to show the effects of the wall and window thickness, and window's glasses for practical wireless mobile communication frequencies.

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  • Dielectric Permittivity Estimation Based On Free Space Method

    A. N. Nguyen, H. Shirai

    Proc. of 2017 IEICE General Conference   CDROM   2017.3

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  • Effect of the Gap Width to the Input Impedance of Dipole Antennas by FDTD Method

    Z. Zheng, H. Shirai

    Proc. of 2017 IEICE General Conference   CDROM   2017.3

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  • A Free Space Permittivity Measurement at Microwave Frequencies for Solid Materials Reviewed

    An Ngoc Nguyen, Hiroshi Shirai

    IEICE TRANSACTIONS ON ELECTRONICS   E100C ( 1 )   52 - 59   2017.1

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    A broadband approach to estimate the relative permittivity of dielectric cuboids has been proposed for materials of weak frequency dispersive characteristic. Our method involves a numerical iterative scheme with appropriate initial values carefully selected to solve for the relative permittivity in a wide range of frequencies. Good agreements between our method and references have been observed for nylon and acrylic samples. An applicable range relation between the minimal thickness, the frequency range and the dielectric property of the material has also been discussed.

    DOI: 10.1587/transele.E100.C.52

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  • Theoretical Limit of the Radiation Efficiency for Electrically Small Self-Resonant Spherical Surface Antennas Reviewed

    Keisuke Fujita, Hiroshi Shirai

    IEICE TRANSACTIONS ON ELECTRONICS   E100C ( 1 )   20 - 26   2017.1

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    Theoretical maximum radiation efficiency of electrically small spherical surface antennas has been derived in this study. The current on the antenna surface is described in terms of vector spherical harmonics, and the radiated and the dissipated powers are calculated to obtain the radiation efficiency. It has been found that non-resonant TM10 mode shows the best radiation efficiency, and a proper combination of TM10 and TE10 modes establishes a resonant spherical surface antenna whose radiation efficiency is bounded by those values of non-resonant TM10 and TE10 modes. As a practical example of the spherical surface antennas, the radiation efficiency of the spherical helix antennas has also been computed to check the validity of our formulation.

    DOI: 10.1587/transele.E100.C.20

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  • Efficient Approximate Solution of Scattering Field by Three-layered Dielectric Slab for Accurate Propagation Analysis Reviewed

    Ryoichi Sato, Hiroshi Shirai

    2017 IEEE INTERNATIONAL CONFERENCE ON COMPUTATIONAL ELECTROMAGNETICS (ICCEM)   117 - 119   2017

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    In this paper, we derive approximate solution of scattering field by three-layered dielectric slab under high frequency condition. To bundle or collect the multiple reflected rays inside the slab into the primary reflected and transmitted rays, high frequency asymptotic approximation technique is used. We call the derived primary rays "collective rays". By using the new reflection/transmission coefficients in the present collective rays instead of the conventional ones, the internal multiple reflections effect can be easily included in ray tracing method without increase of the computational cost, so one can efficiently carry out propagation analysis through indoor/outdoor environments.

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  • Reconstruction of Dielectric Polygonal Scatterers using Electromagnetic Wave Back Scattering Value

    A. Kisumi, H. Shirai

    IEICE Technical Report on Electromagnetic Theory   EMT2016-57   123 - 128   2016.11

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  • A Study on Vehicular Modelings for FDTD Analysis

    T. Ishifuji, Z. Zheng, H. Shirai

    IEICE Technical Report on Electromagnetic Theory   EMT2016-65   177 - 182   2016.11

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  • Hybrid Ray-Mode Analysis of E-Polarized Plane Wave Diffraction by a Thick Slit Reviewed

    Hiroshi Shirai, Masayuki Shimizu, Ryoichi Sato

    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION   64 ( 11 )   4828 - 4835   2016.11

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    A high-frequency asymptotic method has been applied to formulate E-polarized plane wave diffraction by a thick slit. The slit structure is regarded as an open-ended parallel plane waveguide cavity, and the excitation of the waveguide modes and their reradiation are derived from a ray-mode conversion technique. Comparison with another method reveals the validity and effectiveness of our formulation.

    DOI: 10.1109/TAP.2016.2608978

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  • E Polarized Plane Wave Diffraction by a Thick Loaded Slit

    M. Shimizu, H. Shirai, R. Sato

    IEICE Technical Report on Electromagnetic Theory   EMT2016-47   55 - 60   2016.11

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  • Difference on the Radiation Efficiency between Two Spherical Helix Antennas

    K. Fujita, H. Shirai

    Proc. of the 2016 IEICE Society Conference   CDROM   2016.9

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  • On Efficiency Improvement of Simpli ed Ray-launching Method for Indoor Propagation Problem

    R. Sato, H. Shirai

    Proc. of 2016 IEICE Society Conference   CDROM   2016.9

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  • Novel Closed-Form Solutions for Designing Extended-Composite Right/Left-Handed Transmission Lines Reviewed

    H. B. Chu, H. Shirai

    Proc. of 2016 International Conference on Electromagnetics in Advanced Applications   349 - 352   2016.9

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  • Far Field Radiation Pattern Analysis of an Antenna Installed in an Automobile Reviewed

    Z. Zheng, H. Shirai

    Proc. of 2016 URSI Asia-Pacific Radio Science Conference   1038 - 1041   2016.8

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  • New Estimation Method for the Operational Low Frequency End of Antipodal Vivaldi Antennas Reviewed

    Hien Ba Chu, Hiroshi Shirai, Chien Dao Ngoc

    IEICE TRANSACTIONS ON ELECTRONICS   E99C ( 8 )   947 - 955   2016.8

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    A simple approach is presented for designing an antipodal Vivaldi antenna in this paper. A new and better estimation of the low frequency end of the operational range is shown. Final dimensions of the antenna parameters are determined by using the High Frequency Structure Simulator (HFSS). The proposed antenna has a simple configuration but exhibits low return loss, good radiation characteristics, and high and flat gain in the operating ultra wideband frequency range (3.1-10.6 GHz). Lastly, the fabrication has been done along with the specification to confirm the properties by measurements.

    DOI: 10.1587/transele.E99.C.947

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  • Diffraction by Thick and Loaded Slit -E-polarization Case-," Proc. of International Symposium on Electromagnetic Theory Reviewed

    H. Shirai, M. Shimizu, R. Sato

    Proc. of International Symposium on Electromagnetic Theory   665 - 667   2016.8

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  • Wall Thickness Consideration for Indoor EM Propagation Estimation by SBR Method

    T. Hayashi, H. Shirai

    Proc. of 2016 IEICE General Conference   2016 ( C-1-28 )   CDROM - 28   2016.3

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  • Radiation Efficiency Considering Stored Energy Inside Small Thin Spherical Shell Shaped Antennas

    K. Fujita, H. Shirai

    Proc. of 2016 IEICE General Conference   2016 ( B-1-114 )   CDROM - 114   2016.3

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  • A study on electromagnetic wave scatteringform dielectric cylinders

    J. Aiso, H. Shirai

    Proc. of 2016 IEICE General Conference   2016 ( C-1-27 )   CDROM - 27   2016.3

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  • Electromagnetic Plane Wave Diffraction by Loaded N-Slits on Thick Conducting Screen Reviewed

    Ryoichi Sato, Hiroshi Shirai

    IEICE TRANSACTIONS ON ELECTRONICS   E99C ( 1 )   72 - 75   2016.1

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    In this paper, an electromagnetic plane wave diffraction by finite number of loaded thick slits on infinitely long perfectly electric conductor (PEC) screen is analyzed. Here we formulate the problem by utilizing the Kobayashi Potential (KP) method, which is a kind of eigenfunction expansion method in terns of Weber-Schafheitlin discontinuous integrals. The multiple scattering contributions between the slits are analytically included in the formulation. The solution derived here may provide us with precise numerical result, so it may be considered as a reference solution to other numerical and approximate analyses.

    DOI: 10.1587/transele.E99.C.72

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  • Electromagnetic Scattering Analysis from Rectangular Dielectric Cuboids - TE Polarization Reviewed

    An Ngoc Nguyen, Hiroshi Shirai

    IEICE TRANSACTIONS ON ELECTRONICS   E99C ( 1 )   11 - 17   2016.1

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    A high frequency approximation method is proposed to obtain the scattering from rectangular dielectric cuboids. Our formulation is based on a Kirchhoff type aperture integration of the equivalent current sources over the surface of the scattering bodies. The derived formulae have been used to get the radar cross section of cuboids, and the results are compared with those by other methods, such as physical optics, geometrical theory of diffraction, the HFSS simulation and measurements. Good agreement has been observed to confirm the validity of our method.

    DOI: 10.1587/transele.E99.C.11

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  • Diffraction by Thick and Loaded Slit -E-polarization Case- Reviewed

    Hiroshi Shirai, Masayuki Shimizu, Ryoichi Sato

    2016 URSI INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC THEORY (EMTS)   659 - 661   2016

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    A high frequency asymptotic method has been applied to formulate a E-polarized plane wave diffraction by a thick and loaded slit. Internal slit region is considered as a waveguide and the excitations of the waveguide modes are given by a ray-mode conversion method from the multiply bouncing diffracted fields. Comparison with the results by the other method reveals the validity and the effectiveness of our formulation.

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  • Electromagnetic Scattering by Simplified Crack Models on Conducting Ground Plane Reviewed

    Ryochi Sato, Hiroshi Shirai

    2016 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP)   582 - 583   2016

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    This paper analyzes electromagnetic scattering problems for simplified crack models, based on the formulation of the Kobayashi Potential (KP) method. Here, three types of simple crack models, a flanged waveguide, a rectangular trough, and a thick slit, are considered. The derived far zone field representations are utilized to obtain the approximate formulae of the scattered fields for the models.

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  • Ray-mode Conversion Technique Applied to Thick Slit Diffraction Reviewed

    Hiroshi Shirai, Masayuki Shimizu, Ryoichi Sato

    2016 IEEE INTERNATIONAL CONFERENCE ON MATHEMATICAL METHODS IN ELECTROMAGNETIC THEORY (MMET)   43 - 45   2016

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    Ray-mode conversion technique has been applied to formulate a plane wave diffraction by a wide and thick slit perforated in a perfectly conducting screen. The internal field inside the thick slit is first formulated by multiply bouncing reflected and diffracted rays, and this ray summation is converted into a summation of parallel plane waveguide modes through the Poisson summation formula. The total field is then expressed as a summation of successive radiation fields excited by the waveguide modes at the aperture edges. The derived results are used to calculate the far fields and compared with the reference solution. Good agreement has been observed to confirm the validity of our formulation.

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  • Analysis and design of E-CRLH TL characteristics with new closed-form solutions Reviewed

    Hien Ba Chu, Hiroshi Shirai

    Progress In Electromagnetics Research C   68   163 - 178   2016

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    In this study, new closed-form solutions are presented for deriving inductance and capacitance elements of the extended-composite right/left-handed transmission line (E-CRLH TL) unit cell from the cutoff frequencies of right-handed (RH) and left-handed (LH) bands. The characteristics of the E-CRLH TL are investigated for unbalanced, balanced, and mixed cases. The dispersion diagram, Bloch impedance, S-parameters are analyzed by the TL, circuit theories and the Bloch-Floquet theorem. Lastly, the usefulness of our method has been shown in detail by designing the desired characteristics for various cases.

    DOI: 10.2528/PIERC16080103

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  • A Compact D-CRLH Metamaterial Antenna for WLAN and WiMAX Multiband Reviewed

    Hieu Ngoc Quang, Hiroshi Shirai

    2016 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP)   32 - 33   2016

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    This paper presents a compact multiband antenna formed from only one cell of dual composite right left handed transmission line (D-CRLH TL), which employs metamaterial loading on a conventional monopole to attain a certain degree of miniaturization. The proposed configuration is simple as uniplanar structure, and is operating at 2.45, 3.60 and 5.60 GHz, covering the WLANs and WiMAX bands, and its dimension is only 20 x 16 x 1.6 mm(3). The design concepts, the simulation and the experimental results are reported.

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  • Radiation Efficiency of Multi-arm Open-ended Spherical Helix Antennas Reviewed

    Keisuke Fujita, Hiroshi Shirai

    2016 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP)   722 - 723   2016

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    Radiation efficiency of multi-arm open-ended spherical helix antennas has been discussed in this paper. The numerical electromagnetics code (NEC) engine has been utilized for the calculation of their radiation efficiency. It has been found that single-arm Kim-type winding antennas can achieve higher radiation efficiency than that of the Best-type antennas, and non-feeding multi-arms can increase their radiation efficiency.

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  • Evanescent Modal Effect to E Polarized Plane Wave Diffraction by a Wide and Thick Slit Reviewed

    Hiroshi Shirai, Masayuki Shimizu, Ryoichi Sato

    2016 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM   1503 - 1504   2016

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    High frequency asymptotic method has been applied to formulate E-polarized plane wave diffraction by a wide and thick slit. Slit aperture region is considered as a waveguide and excitations of the waveguide modes are given by ray-mode conversion technique. Comparison with the other method reveals the validity and the effectiveness of our formulation.

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  • Ray-mode Conversion Technique Applied To Plane Wave Diffraction By a Thick Slit Reviewed

    H. Shirai, M. Shimizu

    Proc. of Korea-Japan Joint Conference on EMT/EMC/BE   CDROM   2015.11

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  • Dimension Estimation of Quadrangular Dielectric Cylinder from the Surface Scattering Value

    A. Kisumi, H. Shirai

    Technical Report on Electromagnetic Theory, IEICE   ( EMT-2015-64 )   103 - 108   2015.10

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  • Estimation of electromagnetic wave propagation using SBR method

    T. Tabata, H. Shirai

    Technical Report on Electromagnetic Theory, IEICE   ( EMT-2015-70 )   137 - 142   2015.10

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  • A Study on Radiation Characteristics for Electrically Small Spherical Conducting Shell Antennas

    K. Fujita, H. Shirai

    Technical Report on Electromagnetic Theory (EMT), IEICE   ( EMT-2015-74 )   161 - 166   2015.10

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  • Far field radiation pattern analysis of an antenna in an automobile

    Z. Zheng, H. Shirai

    Technical Report on Electromagnetic Theory, IEICE   ( EMT-2015-55 )   57 - 62   2015.10

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  • Evanescent Modal Effect of a Wide and Thick Slit Diffraction

    M.Shimizu, H. Shirai, R.Sato

    Technical Report on Electromagnetic Theory, IEICE   EMT-2015-61   89 - 94   2015.10

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  • The Radiation Efficiency for Resonant Small Spherical Antennas

    K. Fujita, H. Shirai

    Proc. of the 2015 IEICE Society Conferenc   CDROM   2015.9

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  • A Non-Destructive Estimation Method of Permittivity of Dielectric Materials Reviewed

    A. N. Nguyen, H. Shirai

    Proc. of 2015 International Conference on Electromagnetics in Advanced Applications   CDROM   2015.9

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  • Balance Condition of Electromagnetic Stored Energy for Spherical Shaped Homogeneous Antennas

    K. Fujita, H. Shirai

    Proc. of 2015 IEICE General Conference   CDROM   2015.3

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  • A Study on Complex Permittivity Estimation using Time Domain RCS

    J. Aiso, H. Shirai

    Proc. of 2015 IEICE General Conference   CDROM   2015.3

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  • EM Wave Scattering From Simple Crack Model on Conducting Plane

    R. Sato, H. Shirai

    Proc. of 2015 IEICE General Conference   CDROM   2015.3

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  • Theoretical Limitation of the Radiation Efficiency for Homogenous Electrically Small Antennas Reviewed

    Keisuke Fujita, Hiroshi Shirai

    IEICE TRANSACTIONS ON ELECTRONICS   E98C ( 1 )   2 - 7   2015.1

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    Maximum radiation efficiency has been derived for homogeneous electrically small antennas. The spherical wave expansion is utilized to express the radiated field and the current distribution on an antenna, and the radiation efficiency is represented by the current, which is expressed in the spherical wave expansion coefficients and the nonradiating current. By using a concept of the nonradiating current, it is shown that the maximum radiation efficiency is achieved if the antenna shape is spherical. The radiation efficiency of a spherical antenna is maximized by varying the expansion coefficients. This radiation efficiency is compared with that of the antenna which achieves the maximum gain and those of linear antennas. The comparison indicates the validity of our proposed upper limit of the radiation efficiency.

    DOI: 10.1587/transele.E98.C.2

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  • A Numerical Method for the Estimation of Relative Permittivity of Dielectric Materials Reviewed

    A. N. Nguyen, H. Shirai

    PROCEEDINGS OF THE 2015 INTERNATIONAL CONFERENCE ON ELECTROMAGNETICS IN ADVANCED APPLICATIONS (ICEAA)   125 - 128   2015

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    A broadband approach to estimate relative permittivity of dielectric cuboids has been proposed. Our method involves a numerical iterative scheme with appropriate initial values to solve for the permittivity in a wide range of frequency. Good agreement between the method and references has been observed. It is assumed that the material has a weak frequency dispersive characteristic. An applicable range relation between the smallest thickness, the dielectric property of material has also been discussed.

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  • Multiple Edge Interaction Effect to Plane Wave Scattering by a Wide and Thick Slit Reviewed

    Masayuki Shimizu, Hiroshi Shirai, Ryoichi Sato

    2015 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP)   CDROM   2015

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    High frequency ray method has been applied to formulate E-polarized plane wave scattering by a wide and thick slit. Slit aperture region is considered as a waveguide which connects the upper and lower half spaces, and excitations of the waveguide modes are given by edge diffraction at the open end. Multiple edge diffraction effect as well as modal bouncing effect are also considered to improve the accuracy of the scattering field.

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  • Theoretical Study on the Radiation Efficiency of Electrically Small and Thin Spherical Shell Antennas Reviewed

    Keisuke Fujita, Hiroshi Shirai

    2015 1st URSI Atlantic Radio Science Conference (URSI AT-RASC)   CDROM   2015

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  • Effect of Curvature of Antipodal Structure on Vivaldi Antennas Reviewed

    Hien Ba Chu, Hiroshi Shirai, Chien Ngoc Dao

    2015 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION & USNC/URSI NATIONAL RADIO SCIENCE MEETING   2331 - 2332   2015

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    Effect of curvature of antipodal structure on Vivaldi antennas is presented in this paper. The results indicate that inner curvature has a significant impact on the return loss S11. In addition, a new estimation of lower frequency limit is shown. Based on our design, an antipodal Vivaldi antenna has been fabricated and verified its properties through measurements.

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  • Dimension Estimation of Polygonal Dielectric Targets From Surface Reflection RCS Reviewed

    Asuka Kisumi, Hiroshi Shirai

    2015 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP)   CDROM   2015

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    A method has been proposed here to estimate the facet's size of polygonal dielectric targets using the specular reflected RCS. This algorithm has been tested to estimate the size of dielectric cuboids from the measurement data. Good accuracy has been found and the validity of our method is confirmed.

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  • A Compact Tri-Band Metamaterial Antenna for WLAN and WiMAX Applications Reviewed

    H. N. Quang, H. Shirai

    PROCEEDINGS OF THE 2015 INTERNATIONAL CONFERENCE ON ELECTROMAGNETICS IN ADVANCED APPLICATIONS (ICEAA)   133 - 136   2015

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    A compact tri-band metamaterial antenna is presented. The antenna is based on dual composite right/left handed transmission line (D-CRLH TL) which employs metamaterial loading on a conventional monopole to attain a certain degree of miniaturization. The over size of the antenna is 20 x 16 x 1.6 mm(3). The simulated return loss shows that the proposed antenna is suitable for WLAN 2.4/5.5 and WiMAX bands.

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  • `Inverse Numerical Calculation to Determine Relative Permittivity of Lossy Dielectric Materials

    A. N. Nguyen, H. Shirai

    Technical Report of Electromagnetic Theory   85 - 90   2014.11

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  • On the Recognition Of the Concave Metal Polygonal Cylinders

    T. Kurabe, H. Shirai

    Technical Report of Electromagnetic Theory   95 - 100   2014.11

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  • Plane wave scattering analysis on V-shape groove (II)

    J. Hayashi, H. Shirai

    IEE Japan   41 - 46   2014.11

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  • Analysis of indoor electromagnetic wave propagation using SBR method

    T. Tabata, H. Shirai

    Technical Report of Electromagnetic Theory   57 - 62   2014.11

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  • A Study on Radiation Efficiency and its Excitation Fields for Electrically Small Spherical Antennas

    K. Fujita, H. Shirai

    Tecnical Report of Electromagnetic Theory   67 - 72   2014.11

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  • The Radiation Efficiency for Electrically Small Spherical Shell Antennas

    K. Fujita, H. Shirai

    Proc. of the 2014 IEICE Society Conference   CDROM   2014.9

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  • 3D Visualization of Electromagnetic Wave Propagation Reviewed

    Hiroshi Shirai

    IEICE Trans. on Electronics,   J97-C ( 9 )   335 - 341   2014.9

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    Three dimensional visualization has been tested for electromagnetic wave propagation and radiation, which cannot be observed by our own eyes directly. Electric, magnetic, and Poynting vectors radiated from an infinitely small dipole antenna in a free space have been visualized by arrows, which are colored and enlarged according to their strength. Electric and magnetic lines of forces are also calculated from their space distribution, and shown three dimensionally. Radiation from a half-wavelength dipole antenna near a human head model has been simulated by the finite difference time domain (FDTD) method, and resultant time-varying electric field vectors are shown with the head model. The internal electric field inside the human head is utilized to calculate the specific absorption ratio (SAR) at that position, and SAR values are displayed.

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  • A Study on Reflection/transmission Characteristics from Two-layered Dielectric Slab

    R. Sato, H. Shirai

    Proc. of the 2014 IEICE Society Conference   CDROM   2014.9

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  • Radiation directivity of an antenna installed in an automobile Reviewed

    Z. Zheng, H. Shirai

    Proc. of 2014 Progress In Electromagnetics Research Symposium (PIERS)   CDROM   2014.8

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  • Dosimetry Using a Localized Exposure System in the Millimeter-Wave Band for in vivo Studies on Ocular Effects Reviewed

    Kensuke Sasaki, Taiji Sakai, Tomoaki Nagaoka, Kanako Wake, Soichi Watanabe, Masami Kojima, Nailia Hasanova, Hiroshi Sasaki, Kazuyuki Sasaki, Yukihisa Suzuki, Masao Taki, Yoshitsugu Kamimura, Akimasa Hirata, Hiroshi Shirai

    IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES   62 ( 7 )   1554 - 1564   2014.7

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    We developed a millimeter-wave (MMW) exposure system for in vivo experiments for operating frequencies ranging from 24.5 to 95 GHz. The MMWs are localized to the rabbit ocular tissue with a spot-focus lens antenna. The MMW energy absorption and consequent temperature elevation are evaluated by numerical simulation using measured antenna distribution and precisely modeled rabbit ocular data. Results suggest that corneal damage occurs at an incident power density of 300 mW/cm(2) with our exposure system at frequencies from 26.5 to 95 GHz.

    DOI: 10.1109/TMTT.2014.2323011

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  • On the Study of Electromagnetic Wave Scattering from Curved Dielectric Surfaces

    J. Aiso, H. Shirai

    Technical Report of Electromagnetic Theory   53 - 58   2014.7

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  • A study on electromagnetic plane wave scattering by a partially loaded crack on conducting plane

    R. Sato, H. Shirai

    Technical Report of Electromangetic Theory   71 - 74   2014.7

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  • Wave proapgation estimation in city area using SBR method

    H. Shirai, T. Maeda

    Proc. of the 2014 IEICE General Conference   CDROM   2014.3

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  • The upper limit of the radiation efficiency for electrically small antennas

    K. Fujita, H. Shirai

    Proc. of 2014 IEICE General Conference   CDROM   2014.3

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  • On the interpolation of EM propagation estimation by SBR method

    K. Arao, H. Shirai

    2014 IEICE General Conference   CDROM   2014.3

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  • Measuring by Electromagnetic Waves

    H. Shirai

    Re   35 ( 181 )   47 - 50   2014.1

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  • Efficient Reflection/transmission Coefficient by Two-layered Dielectric Slab for Accurate Propagation Analysis Reviewed

    Ryoichi Sato, Hiroshi Shirai

    2014 INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY, TOKYO (EMC'14/TOKYO)   813 - 816   2014

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    In this paper, we propose efficient reflection and transmission coefficients from two-layered dielectric slab for realizing accurate ray-launching propagation analysis, by approximately including multiple reflections effect inside the dielectric slab. In order to precisely execute the ray-launching analysis through the two-layered slab, which is a simplified model of insulating glass window utilized on side wall of modern building, an efficient high frequency approximation is introduced to bundle or collect the multiple reflected rays inside the two-layered slab into the primary ray component. We here call it "collective ray". By utilizing the derived new reflection/transmission coefficients, one can easily include the multiple reflections effect inside the slab without increase of computational time.

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  • On the Radiation Efficiency of Homogeneous Antennas Reviewed

    Keisuke Fujita, Hiroshi Shirai

    2014 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP)   247 - 248   2014

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    Radiation efficiency of homogeneous antennas has been discussed in this paper. The radiated and dissipated powers are expressed in terms of the radiating and nonradiating currents. It has been found that the maximum radiation efficiency can be accomplished by the homogeneous spherical antenna which circumscribes arbitrary antenna shape.

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  • E Polarized Plane Wave Diffraction by a Wide and Thick Slit Reviewed

    Hajime Hasegawa, Hiroshi Shirai, Ryoichi Sato

    2014 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM (APSURSI)   2208 - 2209   2014

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  • Analysis and Design of Antipodal Vivaldi Antenna for UWB Applications Reviewed

    Hien Chu Ba, Hiroshi Shirai, Chien Dao Ngoc

    2014 IEEE FIFTH INTERNATIONAL CONFERENCE ON COMMUNICATIONS AND ELECTRONICS (ICCE)   391 - 394   2014

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    An antipodal Vivaldi antenna for UWB applications is presented in this paper. The proposed antenna is designed with simple structure but presents very good plot impedance characteristic. In addition, the antenna offers high gain and flat gain in the operating bandwidth from 3.1 GHz to 10.6 GHz. The antenna design simulation has been performed by using the commercially available simulation software HFSS 14. The antenna is fabricated on popular substrate FR4 with a dielectric constant of 4.4 and thickness 1.6 mm. The fabricated antenna has been tested for its return loss and directional pattern, and compared with simulated results.

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  • Ray-Mode Conversion Method for High Frequency Scattering Analysis Reviewed

    H. Shirai, R. Sato

    2014 INTERNATIONAL CONFERENCE ON ELECTROMAGNETICS IN ADVANCED APPLICATIONS (ICEAA)   63 - 66   2014

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    Ray-mode conversion technique gives us an alternative description for analyzing electromagnetic scattering from open waveguide/resonance structures. For such structures, modal description may be convenient for expressing the field in the internal structures, while ray description would be suitable for the exterior ones. Ray-modal coupling occurs at the aperture, and its mathematical base is given by the Poisson summation formula.
    In this paper, we shall show some recent development of the ray-mode conversion application to improve the accuracy of the field description by considering the multiple edge interaction and the evanescent modes.

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  • A Study on Electromagnetic Plane Wave Scattering by a Crack on Conducting Plane Reviewed

    R. Sato, H. Shirai

    2014 INTERNATIONAL CONFERENCE ON ELECTROMAGNETICS IN ADVANCED APPLICATIONS (ICEAA)   229 - 232   2014

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    This paper analyzes an electromagnetic plane wave scattering by a crack model on perfectly conducting plane and presents a simple formula for easily calculating two dimensional radar cross section from a material covered crack. Here, a narrow rectangular trough, which is filled by two-layered dielectric material, is utilized as the simple crack model to obtain the rigorous solution of the scattering field. In the formulation, we utilize the Kobayashi Potential (KP) method, which is an eigen function expansion method in terms of Weber-Schafheitlin type discontinuous integrals. Then the simple formula of the scattering field for the case that the aperture width is electrically very narrow is derived by approximating the rigorous solution. By utilizing the derived simple formula, the scattering characteristics for empty, partially material covered, and material filled crack models can be easily investigated.

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  • Reflection/transmission Coefficient for Two-layered Dielectric Slab with Internal Multiple Reflections Reviewed

    Ryoichi Sato, Hiroshi Shirai

    2014 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM (APSURSI)   703 - 704   2014

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    This paper presents novel reflection and transmission coefficients for two-layered dielectric slab, which approximately include multiple reflections inside the slab. H polarization or TE case is here considered. In the derivation, an efficient high frequency approximation is introduced to bundle or collect the multiple reflected rays inside the two-layered slab into the primary ray component. We call them "collective rays". By utilizing the present reflection/transmission coefficients, one can easily include the internal multiple reflections effect in ray-launching analysis without increase of computational time, so these are very efficient for propagation analysis through indoor/outdoor interface as propagation through multi-layered insulating glass window on side wall of modern building.

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  • E Polarized Plane Wave Diffraction by a Thick Conducting Slit

    H. Hasegawa, H. Shirai, R. Sato

    Technical Report on Electromagnetic Theory   31 - 35   2013.11

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    E polarized electromagnetic plane wave diffraction by a wide and thick slit has been analyzed. High frequency ray-mode coupling analysis has been utilized, and the total diffracted field is considered as a summation of successive modal radiation contribution from the slit aperture due to the original modal excitation by the incident plane wave. The derived results are then compared with those obtained by Kobayashi Potential method, and the corresponding H-mode incidence case.

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  • EM Plane Wave Diffraction by a Window Frame Model

    R. Sato, H. Shirai

    IEE Technical Report on Electromagnetic Theory   23 - 28   2013.11

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  • SBR algorithm for including multiple edge diffracted rays

    T. Maeda, H. Shirai

    IEE Technical Report on Electromagnetic Theory   55 - 60   2013.11

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    For stable high speed wireless communication in urban area, it is necessary to install wireless access base station antennas in proper locations. Specially, for non-LOS (line of sight) propagation in a complex urban environment, edge diffracted ray contribution sometimes plays an important role. Shooting and Bouncing Rays (SBR) method is one of the powerful tool for analyzing high frequency electromagnetic wave propagation estimation including edge|rn|diffracted rays. In this report, new algorithm to include multiple edge diffracted rays has been proposed.

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  • Plane Wave Scattering Analysis on V-shape Groove

    J. Hayashi, H. Shirai

    IEE Technical Report of Electromagnetic Theory   19 - 24   2013.11

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    An H polarized electromagnetic plane wave scattering by a V-shape groove on the perfectly conducting ground|rn|has been analyzed. Based on assumption that the groove aperture is sufficiently large compared with wavelength,|rn|Geometrical Theory of Diffraction (GTD) has been utilized for obtaining the edge diffracted waves.

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  • A. N. Nguyen and H. Shirai, ``Electromagnetic wave scattering from dielectric bodies with equivalent current method, Proc. of 2013 International Conference on Electromagnetics in Advanced Applications (ICEAA) Reviewed

    A. N. Nguyen, H. Shirai, Electromagnetic wave scattering, from dielectric, bodies with equivalent current method, Proc. of, International Conference on Electromagnetics in, Advanced Applications (ICEAA

    A. N. Nguyen and H. Shirai, ``Electromagnetic wave scattering from dielectric bodies with equivalent current method, Proc. of 2013 International Conference on Electromagnetics in Advanced Applications (ICEAA)   CDROM   2013.9

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    A general three dimensional formulation of high frequency solution for the scattering field of a dielectric body, which is illuminated by a transverse electric polarized plane wave, is presented. Based on the postulated equivalent currents, scattering far field components are derived. Effects of complex permittivity of material and the multiple bouncing effect caused by the finiteness of scattering body are included in a collective reflection coefficient. Under monostatic conditions, obtained formulae precisely agree with the ones derived from conventional physical optics in the case of a PEC surface. Differences between the two methods are observed in bistatic RCS estimation. Effects of finiteness of scattering body and of polarization on RCS are investigated.

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  • 3D visualization of electromagnetic wave propagation

    H. Shirai

    Proc. of the 2013 IEICE Society Conference   CDROM   2013.9

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  • Reconstruction algorithm of cylindrical metal scatterers using thier monostatic RCS

    H. Shirai

    Technical Report of IEE Electromagnetic Theory   ( EMT-13-105 )   179 - 183   2013.7

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    A target re-construction algorithm has been proposed for cylindrical metal scatterers from the angular Radar Cross Section (RCS) variation. This algorithm is based on the fact that the monostatic RCS return from a plate has its peak value at the specular reflection angle, and the RCS lobe width in the angular variation is related with its plate width. By assuming the target is a polygonal convex cylinder, sizes of their facets are estimated by the local maxima|rn|in the angular RCS variation. Then one may be able to reconstruct the target's shape by connecting all facets in the specular reflection order. For this paper, an algorithm for estimating the curvatures and widths of the smooth curved facets has been augmented with the previously proposed algorthm for flat facets. Our reconstruction algorithm has been tested for several cylindrical targets from numerically calculated and measured RCS values. Pretty|rn|good estimation of the target shape has been observed to show the validity of our method.

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  • Electromagnetic wave scattering from lossy polygonal cylinders Reviewed

    A. N. Nguyen, H. Shirai

    Proc. of 2013 International Symposium on Electromagnetic Theory   CDROM   2013.5

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    In order to study the electromagnetic scattering properties of lossy dielectric polygonal body, Kirchhoff's approximation was used to derive scattering far-field components. Numerical calculations were carried out for some lossy dielectric and metallic rectangular cubes at different frequencies, and then they were compared to measured radar cross section data in order to verify the validity of our approximation. Good agreements were observed in specular reflection directions, especially in the case of electrically large metal cube.

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  • High frequency scattering field calculation from dielectric surfaces

    A. N. Nguyen, H. Shirai

    Proc. of 2013 IEICE General Conference   CDROM   2013.3

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  • The dissipation power of electrically small antennas

    K. Fujita, H. Shirai

    Proc. of 2013 IEICE General Conference   CDROM   2013.3

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    電気的小型アンテナ(ESA) に対するQ, 利得等の各種諸特性の限界値について議論が進んでいる.こうした議論においては,アンテナからの放射界を球面調和関数の和によって表現し,各モードの展開係数を用いて評価する.本報告では,ESA に対する損失電力について,そのアンテナの各励振モードによる依存性について考察した.

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  • High frequency scattering analysis of dielectric surfaces: TM incidence case Reviewed

    An Nguyen Ngoc, Hiroshi Shirai

    Asia-Pacific Microwave Conference Proceedings, APMC   294 - 296   2013

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    Electromagnetic TM polarized plane wave scattering by dielectric surfaces is analyzed by high frequency asymptotic method. The scattering field is estimated from the equivalent currents induced by reflected plane wave on the dielectric surface. Effects of material nature, polarization and finiteness of the dielectric bodies are included in a multiple reflection coefficient. A comparison between theoretical estimations and measurement in the case of a rubber cube suggests a strong connection between the thickness of the body and its RCS values. © 2013 IEEE.

    DOI: 10.1109/APMC.2013.6695124

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  • High efficiency small antenna for WLAN application Reviewed

    Hien Ba Chu, Hiroshi Shirai, Chien Ngoc Dao

    Proceedings of the 2013 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications, IEEE APWC 2013   757 - 760   2013

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    In this paper, a small metamaterial antenna with high efficiency is presented. The antenna is proposed for 2.4 GHz Wireless Local Area Network (WLAN) application. The metamaterial resonant antenna is designed with a mushroom structure which based on the zeroth order resonant characteristic of a composite right/left-handed transmission line (CRLH TL). The antenna is designed on the low-cost FR4 substrate with dielectric constant εr = 4.4 and tan δ= 0.02. The antenna is simulated and optimized by HFSS 14. The simulation results show that antenna has small size and a good bandwidth with range from 2.40-2.48 GHz for return loss S11 less than -10 dB. The proposed antenna offers high efficiency 72-75% in operation bandwidth. The overall dimension of the antenna is 20.0×22.0×1.6 mm3 including the antenna substrate. © 2013 IEEE.

    DOI: 10.1109/APWC.2013.6624903

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  • A Compact CPW-fed C-shaped Patch Antenna For Wireless Communication Reviewed

    Hien Chu Ba, Hiroshi Shirai

    2013 INTERNATIONAL CONFERENCE ON ADVANCED TECHNOLOGIES FOR COMMUNICATIONS (ATC)   443 - 446   2013

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    In this paper, a compact antenna for broadband operation is depicted. A C-shaped patch that based on Chuo University's logo is used to design a monopole radiator. Transmission line theory and the resonator model are adopted to analyze the operating frequencies of the proposed antenna. The bandwidth was enhanced by using the curve of C-shaped patch and CPW feeding method. The proposed antenna was designed and simulated successfully by using HFSS 14. The simulation results show that the antenna has compact size 18.6x17.2 mm(2), a good impedance band with range from 3.9 to 7.6 GHz for return loss S-11 less than -10 dB. The simulated bandwidth reaches 3.7 GHz which is about 72.5% with respect to the center frequency of 5.1 GHz. The antenna can be integrated into wireless communication products such as HIPERLAN/2, IEEE 802.11 a/h/j/n, and WiMAX (4.9-5.85GHz).

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  • A Study of the Antenna Radiation Efficiency for Electrically Small Antennas Reviewed

    Keisuke Fujita, Hiroshi Shirai

    2013 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM (APSURSI)   1522 - 1523   2013

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    Antenna radiation efficiency for electrically small antennas has been discussed in this paper. The radiated field is expressed in terms of spherical harmonic TE and TM modes and radiated and dissipated powers are described by this modal excitation coefficients. By carefully evaluating the above coefficients, upper bound of the radiation efficiency has been estimated.

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  • Electromagnetic wave scattering from dielectric bodies with equivalent current method Reviewed

    A. N. Nguyen, H. Shirai

    Proceedings of the 2013 International Conference on Electromagnetics in Advanced Applications, ICEAA 2013   744 - 747   2013

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    A general three dimensional formulation of high frequency solution for the scattering field of a dielectric body, which is illuminated by a transverse electric polarized plane wave, is presented. Based on the postulated equivalent currents, scattering far field components are derived. Effects of complex permittivity of material and the multiple bouncing effect caused by the finiteness of scattering body are included in a collective reflection coefficient. Under monostatic conditions, obtained formulae precisely agree with the ones derived from conventional physical optics in the case of a PEC surface. Differences between the two methods are observed in bistatic RCS estimation. Effects of finiteness of scattering body and of polarization on RCS are investigated. © 2013 IEEE.

    DOI: 10.1109/ICEAA.2013.6632344

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  • Electromagnetic Plane Wave Diffraction By A Three-Layer Material Loaded Slit Reviewed

    Ryoichi Sato, Hiroshi Shirai

    2013 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM (APSURSI)   1970 - +   2013

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    This paper examines electromagnetic plane wave diffraction by a three-layer dielectric material loaded slit on infinitely long perfect electric conductor (PEC) screen. Here, the Kobayashi Potential (KP) method, which is an analytical eigen function expansion method in terms of the discontinuous characteristics of Weber-Schafheitlin type integrals, is utilized for the analysis. The derived solution obtained by the KP method provides us with precise numerical results, so it may be regarded as a reference solution to other high frequency approximations and numerical techniques. We examine the detailed scattering and diffraction features of the partially loaded slit for H-polarized plane wave incidence, by comparing the results for this analysis with those for empty and material filled cases.

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  • High frequency analysis of modal excitation for |rn|anged parallel plane waveguides

    Y. abe, H. Shirai, R. Sato

    Technical Report, Technical Meeting on Electromagnetic Theory, IEE Japan   EMT-12-150   173 - 178   2012.11

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    High frequency asymptotic analysis has been done for obtaining modal excitation coefficients for the flanged parallel plane waveguides. Previously derived formula has been extended to included multiple edge diffracted contribution between two aperture edges. And also, there is a problem that the excitation coefficients with the transitional modes have discontinuous spike at cut-off frequencies. To improve this behavior, diffraction coefficient has been extended to uniform asymptotic theory of diffraction for complex number. Numerical calculations show that the excitation coefficients with multiple diffraction contribution give us better results for the transitional modes.

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  • SBR algorithm for including diffracted rays

    T. Maeda, H. Shirai

    Technical Report, Technical Meeting on Electromagnetic Theory, IEE Japan   EMT-12-137   95 - 100   2012.11

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    For stable high speed wireless communication in urban area, it is necessary to install wireless access base station antennas in proper locations. For such purpose, one needs a reliable tool for estimating electromagnetic propagation. Ray tracing method is one of the powerful methods for high frequency propagation analysis. For non-LOS (line of sight) propagation in a complex urban environment, diffracted ray contribution sometimes play an important role.|rn|In this report, new algorithm for SBR (Shooting and Bouncing Rays) method to include diffracted rays has been proposed.

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  • SBR propagation estimation for 3D space

    D. Hosoda, H. Shirai, R. Sato

    Technical Report, Technical Meeting on Electromagnetic Theory, IEE Japan   EMT-12-138   101 - 106   2012.11

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  • On the wave propagation estimation using ray approximations

    Hiroshi Shirai

    Proc. of 2012 IEICE Society conference   CDROM   2012.9

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    都市部における集中した携帯電話利用の増加とともに,基地局の効率のよい配置が望まれている.こうした基地局の配置は,広い範囲での電波伝搬強度分布を基に考える必要があり,短時間で効率の良い電波伝搬予測を実測で,または計算シミュレーションによって行うことが求められる[1].|rn|東京を中心とした関東地方の電波伝搬強度について,基地局アンテナ高,使用周波数,伝搬環境,土地利用の状態を考慮して詳細に測定し,その結果をまとめて受信電界強度の中央値を示す曲線を示したOkumura の報告[2] や,その報告から一般化した伝搬環境に対する伝搬損を導出したHata の公式[3] は,世界的にも有名である.|rn|本稿では,広範囲な空間における電波伝搬・散乱量の推定に対して,有力な方法となる光線手法の特徴とその手法を適用する際に注意すべき点について述べる.

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  • Ray-mode coupling analysis for EM plane wave diffraction by two thick slits on infinitely long PEC screen

    R. Sato, H. Shirai

    Proc. of the 2012 IEICE Society Conference   CS-1-6   CDROM   2012.9

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  • GTD analysis for diffraction by a thin slit on infinitely long PEC screen Reviewed

    R. Sato, H. Shirai, Y. Abe

    Proc. of 2012 IEEE International Symposium on Antennas and Propagation   CDROM   2012.7

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    In this paper, we propose a simple and useful extension of the previous GTD|rn|solution for diffracted field by a thin and relatively narrow slit on infinitely|rn|long conducting screen, to treat the internal evanescent modes excited by the|rn|higher order terms due to multiple interactions between the illuminated edges|rn|of the slit. Here, complex propagation angle is introduced for appropriately|rn|evaluating the evanescent modes. To confirm the validity of the proposed extension,|rn|we will make a comparison between the derived solution and that|rn|obtained by the rigorous Kobayashi Potential method. In consequence, the|rn|detailed numerical tests using the present solution will make clear how the|rn|multiple interactions between the illuminated edges and the corresponding|rn|internal modal excitation/coupling contribute to the total radiation characteristics,|rn|for variation of the incident angle and the thickness of the slit.

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  • A Delta-Sigma Modulator Using a Non-uniform Quantizer Adjusted for the Probability Density of Input Signals Reviewed

    Toru Kitayabu, Mao Hagiwara, Hiroyasu Ishikawa, Hiroshi Shirai

    IEICE TRANSACTIONS ON COMMUNICATIONS   E95B ( 7 )   2257 - 2265   2012.7

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    A novel delta-sigma modulator that employs a non-uniform quantizer whose spacing is adjusted by reference to the statistical properties of the input signal is proposed. The proposed delta-sigma modulator has less quantization noise compared to the one that uses a uniform quantizer with the same number of output values. With respect to the quantizer on its own, Lloyd proposed a non-uniform quantizer that is best for minimizing the average quantization noise power. The applicable condition of the method is that the statistical properties of the input signal, the probability density, are given. However, the procedure cannot be directly applied to the quantizer in the delta-sigma modulator because it jeopardizes the modulator's stability. In this paper, a procedure is proposed that determine the spacing of the quantizer with avoiding instability. Simulation results show that the proposed method reduces quantization noise by up to 3.8 dB and 2.8 dB with the input signal having a PAPR of 16 dB and 12 dB, respectively, compared to the one employing a uniform quantizer. Two alternative types of probability density function (PDF) are used in the proposed method for the calculation of the output values. One is the PDF of the input signal to the delta-sigma modulator and the other is an approximated PDF of the input signal to the quantizer inside the delta-sigma modulator. Both approaches are evaluated to find that the latter gives lower quantization noise.

    DOI: 10.1587/transcom.E95.B.2257

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  • GTD Analysis for Diffraction by a Thin Slit on Infinitely Long PEC Screen Reviewed

    Ryoichi Sato, Hiroshi Shirai, Yuji Abe

    Proc. of 2012 IEEE Antennas and Propagation Society International Symposium   CDROM   2012.7

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    In this paper, we propose a simple and useful extension of the previous GTD solution for diffracted field by a thin and relatively narrow slit on infinitely long conducting screen, to treat the internal evanescent modes excited by the higher order terms due to multiple interactions between the illuminated edges of the slit. Here, complex propagation angle is introduced for appropriately evaluating the evanescent modes. To confirm the validity of the proposed extension, we will make a comparison between the derived solution and that obtained by the rigorous Kobayashi Potential method. In consequence, the detailed numerical tests using the present solution will make clear how the multiple interactions between the illuminated edges and the corresponding internal modal excitation/coupling contribute to the total radiation characteristics,|rn|for variation of the incident angle and the thickness of the slit.

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  • Modal excitation analysis at flanged parallel plane waveguides

    Y. Abe, H. Shirai, R. Sato

    Proc. of the 2012 IEICE General Conference   CDROM   2012.3

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  • High Frequency Ray-Mode Coupling Analysis of Plane Wave Diffraction by a Wide and Thick Slit on a Conducting Screen Reviewed

    Hiroshi Shirai, Ryoichi Sato

    IEICE TRANSACTIONS ON ELECTRONICS   E95C ( 1 )   10 - 15   2012.1

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    Diffraction field by a wide and thick slit on a conducting screen has been analyzed. High frequency ray-mode coupling analysis has been utilized, and the total diffracted or radiated field in each region is considered as a summation of successive modal radiation contribution due to the original modal excitation by the incident plane wave. Our derived results are compared with those obtained by other solutions, and good agreement has been observed, and the validity of our formulation is confirmed.

    DOI: 10.1587/transele.E95.C.10

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  • Effect of input-signal statistical property in delta-sigma modulator with non-uniform quantization Reviewed

    Toru Kitayabu, Hiroyasu Ishikawa, Mao Hagiwara, Hiroshi Shirai

    RWW 2012 - Proceedings: IEEE Radio and Wireless Symposium, RWS 2012   183 - 186   2012

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    In this paper, we provide the simulation results for the noise reduction in the delta-sigma modulator with a non-uniform quantizer under various types of input signals. The delta-sigma modulator employs a non-uniform quantizer and adjusts the spacing of the quantizer referring to statistical properties of the input signal to the modulator. It reduces its quantization noise compared to the delta-sigma modulator with the uniform quantizer at the same number of output values. The simulation results showed that the amount of noise reduction varied from 0.15 dB to 4.9 dB depending on the input signal, while the effect is not limited by the architecture of delta-sigma modulators. Moreover, it is shown that the PAPR of the input signal cannot work as an indicator of the amount of the noise reduction. © 2012 IEEE.

    DOI: 10.1109/RWS.2012.6175337

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  • Novel usage of binary tree in SBR algorithm for efficient indoor propagation analysis Reviewed

    Ryoichi Sato, Hiroshi Sato, Hiroshi Shirai

    IEICE ELECTRONICS EXPRESS   9 ( 7 )   673 - 678   2012

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    This letter proposes new usage of the binary tree constructed by fundamental GO ray components in shooting and bouncing rays (SBR) for indoor propagation analysis. The node number of the binary tree is here considered as an important parameter. A couple of small size arrays that can store the passing ray information of both the node number and the position of the pixel considered, and the corresponding ray classification algorithm are newly introduced, not to double-count the same ray with slightly different bouncing angle. Consequently, we realize the big reduction of the computer memory resources consumed for the ray classification especially for wide area analysis, keeping the high accuracy of the SBR method.

    DOI: 10.1587/elex.9.673

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  • High Frequency Asymptotic Analysis of Modal Excitation at Flanged Parallel Plane Waveguides Reviewed

    Yuji Abe, Hiroshi Shirai, Ryoichi Sato

    2012 FOURTH INTERNATIONAL CONFERENCE ON COMMUNICATIONS AND ELECTRONICS (ICCE)   377 - 380   2012

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    Ray analysis has been executed for obtaining modal excitation coefficients at the flanged parallel plane waveguides. Previously derived formula has been extended to include multiple edge diffraction contributions between the aperture edges. By comparing the results by other methods, it has been shown that the contribution due to the doubly edge diffracted rays can improve the excitation coefficients for the transitional waveguide mode.

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  • Reconstruction of Cylindrical Metal Targets Using Their Monostatic RCS Reviewed

    Hiroshi Shirai, Yoshinori Hiramatsu

    2012 INTERNATIONAL CONFERENCE ON ELECTROMAGNETICS IN ADVANCED APPLICATIONS (ICEAA)   113 - 116   2012

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    A simple target reconstruction algorithm has been proposed for cylindrical metal scatterers from the angular Radar Cross Section (RCS) variation. This algorithm is based upon the fact that the monostatic RCS return from a plate has its peak value at the specular reflection angle, and the RCS lobe width in the angular variation is related with its plate width. By assuming the target is a polygonal convex cylinder, sizes of their facets are estimated by the local maxima in the angular RCS variation. Then one may be able to reconstruct the target's shape by connecting all facets in the specular reflection order. Our algorithm for the flat facet case can also extend to handle smooth curved facets. We have applied our reconstruction algorithm for several cylindrical targets from numerically calculated and measured RCS values. Good agreement has been observed to show the validity of our method.

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  • Propagation estimation of 1.5 GHz band wave trasmitted into building

    S. Fujita, Y. Hirota, S. Nanba, Y. Kishi, H. Shirai

    IEEJ Technical Report   EMT-11-119   79 - 84   2011.11

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  • Simplified SBR Propagation Analysis For 3D Indoor Enviroment

    M. Hosono, R. Sato, H. Shirai

    IEEJ Technical Report   EMT-11-120   85 - 89   2011.11

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  • Plane wave diffraction by a partially material loaded slit

    R. Sato, H.Shirai

    IEEJ Technical Report   EMT-11-52 ( 46 )   41 - 44   2011.5

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  • FDTD Cell Size Study for SAR Evaluation for Human Head Exposure to Near EM Field Reviewed

    H. Shirai, J. Ohisa

    Proc. of 2011 Progress In Electromagnetics Research Symposium in Cambridge (PIERS 2011 in Marrakesh)   CDROM   2011.3

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  • Modification of Ray-Launching Method for Accurate 2D Indoor Propagation Analysis Reviewed

    Ryoichi Sato, Hiroshi Shirai

    IEICE TRANSACTIONS ON ELECTRONICS   E94C ( 1 )   55 - 58   2011.1

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    This paper presents an efficient ray-launching method for 2D indoor propagation problem, by including crucial multiple reflection effect inside wall. We hen: focus on the derivation of the reflected and transmitted ray solutions at/through wall when a magnetic source is located in the indoor environment. An efficient approximation, which is called collective ray approximation, is carried out to bundle or collect the internal multiple reflected rays into the primary one. It is resultantly confirmed from the detailed numerical experiments that the derived collective ray solutions can be confidently effective when the internal reflections strongly contribute to the propagation characteristic in the propagation environment, regardless of angle of the incidence.

    DOI: 10.1587/transele.E94.C.55

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  • Analysis of Temperature Elevation in a Rabbit Eye Exposed to Millimeter Wave

    T. Matsuda, T. Sakai, K. Wakw, S. Watanabe, H. Shirai, A. Hirata, K. Sasaki, T, Suzuki

    IEICE Technical Report   EMCJ2010-118 ( 402 )   109 - 114   2011.1

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    Several experiments to investigate ocular effects due to millimeter wave exposure have been performed. In this study, SAR and temperature elevation inside the eye were evaluated numerically using one dimensional model.

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  • Propagation through a window frame structure at outdoor/indoor interface environment Reviewed

    Ryoichi Sato, Hiroshi Shirai

    IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)   2379 - 2382   2011

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    This paper examines specific propagation characteristics for a simple outdoor/indoor interface environment, by analyzing diffraction problem for wide aperture slit in an infinitely long PEC screen. High frequency asymptotic ray technique is applied to analyze the diffraction problem. According to the ray-mode coupling analysis, the total diffracted or radiated field in each region is considered as a summation of successive modal radiation contribution due to the original modal excitation by the incident plane wave. The successive process for generating internal higher modal reflection and external modal radiation fields continues until all the energy inside the slit region is completely consumed. The validity of the derived solution is confirmed by comparing with the other analytical reference one for both width and thickness variations. © 2011 IEEE.

    DOI: 10.1109/APS.2011.5996999

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  • Propagation Through A Window Frame Structure At Outdoor/indoor Interface Environment Reviewed

    Ryoichi Sato, Hiroshi Shirai

    2011 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (APSURSI)   2379 - 2382   2011

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    This paper examines specific propagation characteristics for a simple outdoor/indoor interface environment, by analyzing diffraction problem for wide aperture slit in an infinitely long PEC screen. High frequency asymptotic ray technique is applied to analyze the diffraction problem. According to the ray-mode coupling analysis, the total diffracted or radiated field in each region is considered as a summation of successive modal radiation contribution due to the original modal excitation by the incident plane wave. The successive process for generating internal higher modal reflection and external modal radiation fields continues until all the energy inside the slit region is completely consumed. The validity of the derived solution is confirmed by comparing with the other analytical reference one for both width and thickness variations.

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  • Delta-Sigma Modulator with Non-Uniform Quantization Reviewed

    Mao Hagiwara, Toru Kitayabu, Hiroyasu Ishikawa, Hiroshi Shirai

    2011 IEEE RADIO AND WIRELESS SYMPOSIUM (RWS)   351 - 354   2011

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    In this paper, a novel delta-sigma modulator which has a non-uniform quantizer is proposed. The step sizes of a non-uniform quantizer are, in general, uniquely determined by the probability density function (PDF) of an input signal amplitude, while delta-sigma modulators usually become unstable when the non-uniform quantizer is directly applied to them. It is found that the proposed delta-sigma modulator reduces a quantization noise and works in a stable condition. To guarantee the stability of the delta-sigma modulator, the maximum output value of the quantizer is fixed at a certain value. The rest of the output and threshold values of the non-uniform quantizer are determined by the PDF of the input signal amplitude. The simulation results show that the quantization noise power is reduced by up to 2.90 dB when the non-uniform quantizer is applied.

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  • Propagation Through A Window Frame Structure At Outdoor/indoor Interface Environment Reviewed

    Ryoichi Sato, Hiroshi Shirai

    2011 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (APSURSI)   2379 - 2382   2011

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    This paper examines specific propagation characteristics for a simple outdoor/indoor interface environment, by analyzing diffraction problem for wide aperture slit in an infinitely long PEC screen. High frequency asymptotic ray technique is applied to analyze the diffraction problem. According to the ray-mode coupling analysis, the total diffracted or radiated field in each region is considered as a summation of successive modal radiation contribution due to the original modal excitation by the incident plane wave. The successive process for generating internal higher modal reflection and external modal radiation fields continues until all the energy inside the slit region is completely consumed. The validity of the derived solution is confirmed by comparing with the other analytical reference one for both width and thickness variations.

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  • A study on quantization and visualization of human model for analyzing human exposure to the EM field

    J. Ishii, H. Shirai

    IEEJ Technical Report   EMT-10-111   2010.11

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  • Changes in field uniformity characteristics of a reverberation chamber with transmitting antenna direction

    Eugene Rhee, Hiroshi Shirai

    IEE Technical Report   EMT-10-132   2010.11

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  • Electromagnetic Plane Wave Diffraction by a Wide Slit on Conducting Plane with Finite Thickness Reviewed

    R. Sato, H. Shirai

    Proc. of 2010 Asia Pacific Radio Science Conference (APRASC 2010)   CDROM   2010.9

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  • Complex Permittivity Estimation by Free Space Method Using Specular Reflected RCS Reviewed

    M. Ishikawa, H. Shirai

    Proc. of 2010 Progress In Electromagnetics Research Symposium in Cambridge (PIERS 2010 in Cambridge)   CDROM   2010.7

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  • Parameter Variation Effects on Temperature Elevation in a Steady-state, One-dimensional, Thermal Model for Millimeter Wave Exposure of One- and Three-layer Human Tissue Reviewed

    A. Kanezaki, A, Hirata, S. Watanabe, H. Shirai

    Physics in Medicine and Biology   55   4647 - 4659   2010.7

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    The present study describes theoretical parametric analysis of the steady-state temperature elevation in one-dimensional three-layer (skin, fat and muscle) and one-layer (skin only) models due to millimeter-wave exposure. The motivation of this fundamental investigation is that some variability of warmth sensation in the human skin has been reported. An analytical solution for a bioheat equation was derived by using the Laplace transform for the one-dimensional human models. Approximate expressions were obtained to investigate the dependence of temperature elevation on different thermal and tissue thickness parameters.

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  • A Study on Quantization Noise Reduction of Delta-Sigma Modulator with Nonuniform Quantization

    Mao Hagiwara, Toru Kitayabu, Hiroyasu Ishikawa, Hiroshi Shirai

    Proc. of 2010 IEICE General Conference   B-5-76   2010.3

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  • Effectiveness of a one-dimension model for millimeter-wave exposure experiments

    Tomohiro Matsuda, Taiji Sakai, rn|Soichi Watanabe, Kanako Wake, Hiroshi Shirai

    Proc. of 2010 IEICE General Conference   B-1-186   186 - 186   2010.3

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  • Complex Permittivity Estimation From Free Space RCS Measurement Reviewed

    Hiroshi Shirai, Masayuki Ishikawa

    2010 THIRD INTERNATIONAL CONFERENCE ON COMMUNICATIONS AND ELECTRONICS (ICCE)   290 - 293   2010

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    Non-destructive and non-contacting estimation of the complex permittivity of the solid materials has been proposed using the monostatic RCS measurement from the specular reflection surface. In order to isolate the surface reflection contribution from the total scattering response, time gating method is utilized. The frequency domain RCS is measured first at a certain frequency band, and the corresponding time domain result is calculated via inverse Fourier Transformation. After identifying the surface reflection contribution and selecting it with a certain time width, Fourier transformation is used to obtain the desired surface response in the frequency domain. These RCS results are then utilized to estimate the surface reflection coefficients and their permittivities. The proposed method has been tested to evaluate the permittivities of cubic granite and synthetic phantom material, and the results are compared with those obtained by a coaxial probe method. Good agreement has been found between them and the validity of our method has been confirmed.

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  • Propagation Analysis for a Simplified Indoor/outdoor Interface Model Reviewed

    Ryoichi Sato, Hiroshi Shirai

    2010 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM   CDROM   2010

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  • 非一様量子化器を用いたΔΣ変調器の量子化雑音低減に関する一検討

    M. Hagiwara, T, Kitayabu, H. Ishikawa, H. Shirai

    IEICE Technical Report on Radio Communication System   RCS-109-341   179 - 184   2009.12

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  • A study on permittivity estimation of the targets from their radar cross sections

    M. Ishikawa, H. Shirai

    IEEJ Technical Report   ( EMT-09-131 )   45 - 50   2009.11

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  • Non-contacting Estimation of Complex Permittivity Using RCS Measurement Reviewed

    Masayuki Ishikawa, Hiroshi Shirai

    Proc. of 2009 International Symposium on Antennas and Propagation (ISAP 2009)   CDROM   2009.10

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  • Effects of dielectric permittivities on skin heating due to millimeter wave exposure Reviewed

    Akio Kanezaki, Akimasa Hirata, Soichi Watanabe, Hiroshi Shirai

    BIOMEDICAL ENGINEERING ONLINE   8   2009.9

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    Background: Because the possibility of millimeter wave (MMW) exposure has increased, public concern about the health issues due to electromagnetic radiation has also increased. While many studies have been conducted for MMW exposure, the effect of dielectric permittivities on skin heating in multilayer/heterogeneous human-body models have not been adequately investigated. This is partly due to the fact that a detailed investigation of skin heating in a multilayer model by computational methods is difficult since many parameters are involved. In the present study, therefore, theoretical analyses were conducted to investigate the relationship between dielectric permittivities and MMW-induced skin heating in a one-dimensional three-layer model (skin, fat, and muscle).
    Methods: Approximate expressions were derived for the temperature elevation and temperature difference in the skin due to MMW exposure from analytical solutions for the temperature distribution. First, the power absorption distribution was approximated from the analytical solution for a one-layer model (skin only). Then, the analytical expression of the temperature in the three-layer model was simplified on the basis of the proposal in our previous study. By examining the approximate expressions, the dominant term influencing skin heating was clarified to identify the effects of the dielectric permittivities. Finally, the effects of dielectric permittivities were clarified by applying partial differentiation to the derived dominant term.
    Results: Skin heating can be characterized by the parameters associated with the dielectric permittivities, independently of morphological and thermal parameters. With the derived expressions, it was first clarified that skin heating correlates with the total power absorbed in the skin rather than the specific absorption rate (SAR) at the skin surface or the incident power density. Using Debye-type expression we next investigated the effect of frequency dispersion on the complex relative permittivity of tissue. The parametric study on the total power absorbed in the skin showed that skin heating increases as the static permittivity and static conductivity decrease. In addition, the maximum temperature elevation on the body surface was approximately 1.6 times that of the minimum case. This difference is smaller than the difference caused by the thermal and morphological parameters reported in our previous study.
    Conclusion: This paper analytically clarified the effects of dielectric permittivities on the thermally steady state temperature elevation and the temperature difference in the skin of a one-dimensional three-layer model due to MMW exposure.

    DOI: 10.1186/1475-925X-8-20

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  • International Communication Skill Acquired through Ph.D. Degree Study

    Hiroshi Shirai

    IEICE Journal   92 ( 5 )   386 - 389   2009.5

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    米国大学の大学院への留学を通した、学生生活、Ph.D.取得やポストドクターとしての研究生活等を通して体験した、海外の大学における研究教育活動・環境と日本のそれとの違いについて紹介する。また帰国後、現在までに到る国際共同研究や研究交流を通して日ごろ感じていることについて述べる。

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  • Propagation Characteristics for a Simplified Indoor/Outdoor Interface Model Reviewed

    Ryoichi Sato, Hiroshi Shirai

    Proc. of 2009 Korea-Japan Joint Conference on AP/EMC/EMT   263 - 266   2009.5

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  • RCS値からの複素誘電率推定法に関する考察-時間領域による結果-

    M. Ishikawa, S. Kojima, H. Shirai

    Proc. of 2009 IEICE General Conference   C-1-4   2009.3

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  • Efficient Ray-launching Analysis for Indoor Propagation Including Multiple Reflection Effect Inside Walls Reviewed

    R. Sato, H. Shirai

    ICEAA: 2009 INTERNATIONAL CONFERENCE ON ELECTROMAGNETICS IN ADVANCED APPLICATIONS, VOLS 1 AND 2   756 - +   2009

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    This paper proposes an efficient modification of 2D ray-launching method, by including multiple reflection effect inside wall for indoor environment. An efficient approximation is carried out to bundle or collect the internal multiple reflected rays into the primary one. This approximation is called collective ray approach. We here focus on the derivation of the approximate solution for H (or Vertical) polarized incident case. Resultantly, it is confirmed from the detailed considerations that the present collective ray solutions can be confidently utilized in particular when the internal reflections strongly contribute to the propagation characteristic of the considered indoor environment.

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  • Efficient ray-launching method for 2D indoor propagation analysis Reviewed

    Ryoichi Sato, Hiroshi Shirai

    IEICE Transactions on Electronics   E92-C ( 1 )   40 - 45   2009

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    This paper presents an easy and efficient modification of simplified 2D ray-launching method, by approximately including multiple reflection effect inside walls for indoor environment. In order to precisely carry out the ray-launching procedure inside lossy wall, a simple modification using a true real refraction angle is first introduced, instead of complex one. Furthermore, an efficient approximation is carried out to collect the internal multiple reflected rays into the primary one. We here call it collective ray approach. Consequently, it is confirmed from the detailed considerations that the present ray representations obtained by introducing the real refraction angle are well suitable for indoor propagation analysis, and in particular the collective ray solution can be utilized confidently even when the internal reflections strongly contribute to the propagation feature of the considered indoor environment. © 2009 The Institute of Electronics, Information and Communication Engineers.

    DOI: 10.1587/transele.E92.C.40

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  • On Multiple Scattering Between Slits in an Infinite PEC Screen Reviewed

    Ryoichi Sato, Hiroshi Shirai

    2009 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM AND USNC/URSI NATIONAL RADIO SCIENCE MEETING, VOLS 1-6   2348 - +   2009

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  • 外部から建物内へ透過する電波の近似推定法の検討

    T. Nakanishi, H. Shirai, K. Yonezawa, T. Inoue

    IEEJ Technical Report on EMT   EMT-08-117   2008.11

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  • 人体近傍に置かれたアンテナからの放射解析とその可視化表現

    K. Maekawa, H. Shirai

    IEEJ Technical Report on EMT   EMT-08-115   2008.11

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  • ミリ波帯電波照射による体表温度上昇に関与した電気的特性の検討

    A. Kanezaki, S. Watanabe, A. Hirata, H. Shirai

    IEEJ Technical Report on EMT   EMT-08-97   2008.11

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  • 1-100 GHz帯平面波照射による一次元人体モデル内SARの周波数特性

    A. Kanezaki, T. Nagaoka, S. Watanabe, H. Shirai

    Proc. of 2008 IEICE Society Conference   B-4-27   2008.9

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  • Theoretical Analysis of Temperature Elevation in a Human Body Exposed to Millimeter Wave Reviewed

    A. Kanezaki, T. Sakai, S. Watanabe, A. HIRATA, H. SHIRAI

    Proc. of Progess in Elecromagnetics Research Symposium 2008 in Cambridge   2008.7

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  • 散乱断面積からの複素誘電率推定法に関する考察

    S. Kojima, M. Ishikawa, H. Shirai

    IEEJ Technical Report on EMT   EMT-08-89   2008.7

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  • 理論解析に基づくミリ波帯電波照射による体表温度上昇の層構造依存性に関する検討

    A. Kanezaki, S. Watanabe, A. Hirata, H. Shirai

    IEICE Technical Report on EMC   EMCJ-2008-20 ( 97 )   77 - 82   2008.6

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  • 電磁界の可視化表現

    K. Maekawa, H. Shirai

    Proc. of 2008 IEICE General Conference   CS-1-12   2008.3

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  • ミリ波帯電波照射による円筒モデル内のSAR解析

    A. Kanezaki, T. Sakai, S. Watanabe, H. Shirai

    Proc. of 2008 IEICE General Conference   B-4-53   2008.3

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  • 後方散乱断面積を用いた柱状散乱体の形状認識とその可視化

    Y. Nakamizo, H. Shirai

    Proc. of 2008 IEICE General Conference   CS-1-11   2008.3

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  • Simplified Ray-launching Analysis for Indoor Propagation Including Multiple Reflection Effect Inside Walls Reviewed

    Ryoichi Sato, Hiroshi Shirai

    2008 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM, VOLS 1-9   492 - +   2008

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  • THEORETICAL ANALYSIS FOR TEMPERATURE ELEVATION OF HUMAN BODY DUE TO MILLIMETER WAVE EXPOSURE Reviewed

    A. Kanezaki, S. Watanabe, A. Hirata, H. Shirai

    2008 CAIRO INTERNATIONAL BIOMEDICAL ENGINEERING CONFERENCE   362 - +   2008

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    This paper investigated the analytical solution of the temperature elevation in one-dimensional human model due to millimeter wave exposure for parametric analysis. The analytical solution of the bioheat equation for the one-dimensional three-layer model has been derived using the Laplace Transform. Temperature distribution obtained from the analytical solution is compared with those derived from a numerical difference method. Good agreement has been found between them, suggesting the validity of our analytical solution. The derived expression is useful to clarify the effects of biological parameters on the temperature elevation.

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  • NLOS path loss evaluation for street-cell environment Reviewed

    Amornchai Amornthipparat, Hiroshi Shirai, Kenya Yonezawa, Takashi Inoue

    2008 IEEE RADIO AND WIRELESS SYMPOSIUM, VOLS 1 AND 2   603 - +   2008

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    Non Line of Sight (NLOS) path loss has been investigated by using the Shooting and Bouncing Rays (SBR) method. Two building layouts; continuously connected and non-connected building layouts, are used to check the street propagation characteristics and leakage effect due to the building gaps. Based on the statistical data numerically generated buildings are placed along the streets and path loss are evaluated along them. It is found that the predictions by ITU-R model give us somewhat less path loss for our street-cell models.

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  • Street-Cell NLOS Path Loss Estimation using SBR Method Reviewed

    A. Amornthipparat, H. Shirai, K. Yonezawa, T. Inoue, M. Hatori

    Proc. of 2007 Asia-Pacific Microwave Conference   2007.12

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  • 損失壁透過におけるレイランチング法の精度改善について

    R. Sato, H. Shirai

    IEEJ Technical Report on EMT   EMT-07-86   2007.10

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  • ミリ波帯電波照射による体温上昇の理論解析による検討

    A. Kanezaki, T. Sakai, S. Watanabe, A. Hirata, H. Shirai

    IEEJ Technical Report on EMT   EMT-07-130 ( 115 )   91 - 96   2007.10

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  • 周波数及び時間領域におけるRCS値を用いた柱状散乱体の形状認識

    Y. Nakamizo, H. Shirai, Y. Hiramatsu

    IEEJ Technical Report on EMT   EMT-07-96 ( 81 )   91 - 96   2007.10

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  • 2信号同時受信におけるサンプリング周波数選択方法

    K. Kimura, T. Kitayabu, T. Maeyama, H. Shirai

    Proc. of 2007 IEICE Society Conference   B-17-16   494 - 494   2007.9

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  • 畳込み符号化QAM変調を用いる直交周波数分割多元接続方式におけるインタリーブ最適化に関する一検討

    T. Inoue, R. Kimura, R. Funada, H. Harada, H. Shirai

    Proc. of 2007 IEICE Society Conference   B-5-18   2007.9

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  • 3次元SBR法を用いた市街地電波伝搬解析

    T. Hasunuma, T. Hayashi, A. Yamamoto, H. Shirai, K. Ogawa, K. Otoi

    Proc. of 2007 IEICE Society Conference   B-1-15   2007.9

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  • ミリ波帯電波照射時の温度上昇に体温調節機能が与える影響

    A. Kanezaki, T. Sakai, S. Watanabe, A. Hirata, H. Shirai

    Proc. of 2007 IEICE Society Conference   B-4-24   2007.9

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  • Empirical investigation of the LOS propagation characteristics on an undulating road for millimeter wave inter-vehicle communication Reviewed

    Atsushi Yamamoto, Koichi Ogawa, Hiroshi Shirai

    IEICE TRANSACTIONS ON ELECTRONICS   E90C ( 9 )   1807 - 1815   2007.9

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    We investigated the radio propagation characteristics for line-of-sight (LOS) inter-vehicle communication (IVC) at 60 GHz on an actual road with an undulating surface. Radio propagation tests between two moving vehicles were carried out on a test course. From this, it was found that the measured received power on the actual road and the results calculated for a flat road approximately follow logarithmic normal distributions. To investigate this phenomenon in detail, a propagation test between two stationary vehicles on a road was performed. Furthermore, calculations using geometrical optics taking road undulation into consideration demonstrated that undulation in the road can cause variations in the received power that follow a logarithmic normal distribution. Finally, the received power for moving vehicles on an undulating road was calculated using the model.

    DOI: 10.1093/ietele/e90-c.9.1807

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  • Electromagnetic Wave Progpagation Estimation by 3-D SBR Method Reviewed

    H. Shirai, R. Sato, K. Otoi

    Proc. of 2007 International Conference on Electromagnetics in Advanced Applications   2007.9

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  • Reconstruction Scheme for Polygonal Cylindrical Targets with Curved Surfaces Reviewed

    H. Shirai, Y. Hiramatsu

    Proc. of 2007 Progress in Electromagnetics Research Symposium   2007.8

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  • Effects of Parameters of a Dosimetric Human Model on Temperature Elevation Due to Millimeter-Wave Exposure Reviewed

    A. Kanezaki, T. Sakai, S. Watanabe, H. Shirai

    Proc. of 2007 Progress in Electromagnetics Research Symposium   2007.8

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  • Effects of ear shape and head size on simulated head exposure to a cellular phone Reviewed

    Shoji Mochizuki, Haruhiko Wakayanagi, Tetsuya Hamadia, Soichi Watanabe, Masao Taki, Yukio Yamanaka, Hiroshi Shirai

    IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY   49 ( 3 )   512 - 518   2007.8

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    The dependence of the specific absorption rate (SAR) on ear shape and head size have been investigated using human-head and cellular-phone models. Cubical and realistic head models were used. Various ear shapes were used with the cubical head model whereas a low-loss thin ear or a lossy realistic ear was used with the realistic head models. The SAR distribution depends significantly on the shape of the ear, regardless of the head model. The effects of the head size have been investigated using a 90th-percentile head model and a Japanese-average head model. The head size has considerably less effect than the ear shape. The measurement results have been validated by numerical calculation, and support the use of the specific anthropomorphic mannequin (SAM) standard head model.

    DOI: 10.1109/TEMC.2007.902189

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  • A Propagation Model Considering the Effect of Windows for 60GHz Automotive Radio Communications Reviewed

    A. Yamamoto, K. Ogawa, T. Horimatsu, K. Sato, M. Fujise, H. Shirai

    Proc. of 3rd International Conference on Electromagnetic Near-Field Characterization and Imaging   2007.6

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  • 皮膚組織の含水率がミリ波帯電波照射時の温度上昇に与える影響

    A. Kanezaki, T. Sakai, S. Watanbe, H. Shirai

    IEICE Technocal Report on EMC   EMCJ-2007-3   13 - 18   2007.4

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  • 同一周波数繰り返しDPC-OF/TDMAシステムにおける高速フェージング環境下で の逐次型チャネル推定を用いた下りリンク制御情報スロットの最尤推定受信法に関する検討

    M. Kamiyama, R. Funada, R. Kimura, H. Harada, H. Shirai

    IEICE Technical Report on Wireless Communication System   RCS-2006-183 ( 478 )   49 - 54   2007.1

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  • 並列伝送化されたPR-DSMAプロトコルの移動通信環境における基礎伝送特性

    吉房 裕司, 原田 博司, 白井 宏

    Technical Report of IEICE   RCS2006-201   37 - 42   2007.1

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  • Accurate ray-launching analysis for indoor propagation through a high lossy wall Reviewed

    Ryoichi Sato, Hiroshi Shirai

    2007 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM, VOLS 1-12   2764 - +   2007

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  • Cyclic shifted-and-extended codes based on a Quasi-Orthogonal sequence for a CDM transmission scheme Reviewed

    Kazuyuki Shimezawa, Hiroshi Harada, Hiroshi Shirai

    IEICE TRANSACTIONS ON COMMUNICATIONS   E89B ( 11 )   2998 - 3007   2006.11

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    We have developed a code-division-multiplexing (CDM) transmission scheme for future road-vehicle communication systems, which uses cyclic shifted-and-extended (CSE) codes generated from a basic code with superior auto-correlation characteristics. This paper proposes to use a Quasi-Orthogonal (QO) sequence as the basic code. Its auto-correlation values are zero except at zero and middle shifts. When the CDM transmission is performed by the CSE codes based on the QO sequence, a desired correlation value is, at a receiver, interfered by the auto-correlation value at middle shift. Therefore, an elimination technique for the interfered correlation value is proposed and realizes zero cross-correlation characteristics within the cyclical shift interval. The new CDM transmission scheme based on the proposed scheme is evaluated by computer simulations in terms of the bit-error-rate performance.

    DOI: 10.1093/ietcom/e89-b.11.2998

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  • Prediction of Road Undulation Based on Two-Ray Model

    Amornchai Amornthipparat, Hiroshi Shirai, Atsushi Yamamoto, Koichi Ogawa

    IEEJ Technical Report on EMT   EMT-06-98   2006.10

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  • レイランチング法を用いた簡易室内伝搬解析~損失媒質透過の場合の精度向上について~

    R. Sato, H. Sato, H. Shirai

    IEEJ Technocal Meeting on EMT   EMT-06-100 ( 86 )   79 - 84   2006.10

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  • Road Undulation Estimation Based on Two-Ray LOS Propagation Model Reviewed

    Amonrnchai Amornthipparat, Hiroshi Shirai, Atsushi Yamamoto, Koichi Ogawa

    Proc. of First International Conference on Communications and Electronics   273 - 276   2006.10

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  • Reconstruction of Polygonal Cylindrical Targets from Their Monostatic RCS Reviewed

    H. Shirai

    Proc. of IV-th International Workshop on Electromagnetic Wave Scattering (EWS2006)   3   9 - 13   2006.9

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  • EM Wave Indoor Propagation Analysis by 3-D Adaptive SBR Method Reviewed

    K. Otoi, H. Wakabayashi, T. Ohno, A. Yamamoto, H. Shirai, K. Ogawa

    Proc. of 2006 Korea-Japan AP/EMCJ/EMT Joint Conference (KJJC-AP/EMCJ/EMT'06)   273 - 276   2006.9

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  • 3次元SBR法を用いた室内における電磁波伝搬解析

    K. Otoi, H. Wakabayashi, K. Ohno, T. Yamamoto, H. Shirai, K. Ogawa

    Proc. of 2006 IEICE Society Conference   B-1-46   2006.9

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  • 1セル繰り返しDPC-OF/TDMAシステムにおける下りリンク制御情報スロットの最尤推定受信法

    M. Kamiyama, R. Kimura, R. Funada, H. Harada, H. Shirai

    Proc. of 2006 IEICE Society Conference   B-5-10   2006.9

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  • アンダーサンプリングにおけるサンプリング周波数選択方法

    K. Kimura, Y. Kunisawa, H. Shirai

    Proc. of 2006 IEICE Society Conference   B-17-4   2006.9

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  • Application of a MoM/FDTD-Hybred Method to Herical Dipole Antenna Reviewed

    P. Pongpaibool, S. Watanabe, S. Mochizuki, H. Shirai, T. Uno

    Proc. of EMC Europe 2006   2006.9

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  • Target Estimation Algorithm for Large Polygonal PEC Bodies Using Their RCS Data Reviewed

    H. Shirai

    Proc. of 2006 China-Japan Advanced Workshop on Antennas and Microwave Technology   2006.8

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  • Numerical Simulation of Helical Dipole Antenna Using the MoM/FDTD-Hybrid Method Reviewed

    P. Pongpaibool, S. Watanabe, S. Mochizuki, H. Shirai, T. Uno

    Proc. of 2006 Progress in Electromagnetics Research Symposium   2006.8

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  • A Ray-launching Estimation For Simple Indoor Wave Propagation Through High Lossy Walls Reviewed

    R. Sato, H. Sato, H. Shirai

    Proc. of 2006 Progress in Electromagnetics Research Symposium   2006.8

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  • Accuracy Improvement of Ray-launching Approach for Indoor Wave Propagation Through High Lossy Walls Reviewed

    R. Sato, H. Sato, H. Shirai

    Proc. of 2006 IEEE International Symposium on Antennas and Propagation   2006.7

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  • Spatial-Dependence of Warmth Sensation Caused by Millimeter-Wave Exposure Reviewed

    S. Watanabe, T. Konno, M. Hanazawa, K. Wake, Y. Suzuki, M. Kouzai, A. Nishikata, H. Shirai, M. Taki

    Proc. of 2006 Bioelectromagnetics Meeting   2006.6

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  • A study on FDTD cell size for evaluating human head exposure to near EM field Reviewed

    H. Shirai, J. Ohisa, S. Mochizuki

    Proc. of 2006 ACES Conferences on Applied Computational Electromagnetics   2006.3

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  • Reconstruction of polygonal cylindrical targets with curved surfaces from their monostatic RCS Reviewed

    H Shirai, Y Hiramatsu, M Suzuki

    IEICE TRANSACTIONS ON ELECTRONICS   E88C ( 12 )   2289 - 2294   2005.12

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    Target reconstruction algorithm from its monostatic radar cross section (RCS) has been proposed for polygonal cylinders with curved surfaces. This algorithm is based on our previous finding that the main contribution to the back scattering is due to edge diffracted fields excited at a facet of nearly specular reflection direction. Dimension of this constitutive facet of the target is estimated from the local maxima and its lobe width in the angular RCS variation. Half and quarter circular cylinders are used as canonical scattering objects, and their measured and numerically simulated monostatic RCS values have been studied extensively to find scattering pattern characteristic difference between flat and circularly curved surfaces. Thus estimated constitutive facets are connected in order, and this procedure will be continued until the distance between the first and the final edges would be minimized. Our algorithm has been tested for other targets, and it is found that it works well for predicting metal convex targets with flat and curved facets.

    DOI: 10.1093/ietele/e88-c.12.2289

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  • A new sampling frequency selection scheme in undersampling systems Reviewed

    Y Kunisawa, N Sahara, H Shirai, H Iwai

    IEICE TRANSACTIONS ON COMMUNICATIONS   E88B ( 11 )   4170 - 4175   2005.11

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    In software defined radio systems, placing the analog-to-digital converter (ADC) near the antenna part in the block diagram of the receiver is desired to improve the flexibility of the system. The radio frequency (RF) sampling method in which the received signal is sampled at the RF stage, realizes such structure. The undersampling is a potential method to sample the RF signal using the existing consumer ADCs because high speed ADCs are required in the traditional methods, such as Nyquist sampling or the oversampling of the RF signal. This paper presents a technique to determine the minimum sampling frequency to undersample the separated multiple wireless systems simultaneously. In addition, this paper proposes a frequency selecting scheme that enables selection of a lower sampling frequency by receiving at least the desired transmission channels in the wireless system signals. This paper also provides a result of performance analysis of the proposed scheme.

    DOI: 10.1093/ietcom/e88-b.11.4170

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  • 高周波近似による柱状散乱体の曲面推定-曲率が変化する場合-

    Y. Hiramatsu, H. Shirai

    IEEJ Technical Report on EMT   EMT-05-67   37 - 42   2005.11

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  • A Study of Warmth Sensation Produced by Millimeter Wave Exposure Reviewed

    T. Konno, M. Hanazawa, S. Watanabe, M. Taki, H. Shirai

    Proc. of 28th General Assembly of International Union of Radio Science   2005.10

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  • Reconstruction of cylindrical metal targets using their Frequency and time domain RCS values Reviewed

    H. Shirai, Y. Hiramatsu

    Proc. of 28th General Assembly of International Union of Radio Science   2005.10

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  • Electromagnetic wave propagation estimation for wireless communication system Reviewed

    H. Shirai

    Proc. of 2005 International Conference on Electromagnetics in Advanced Applications   2005.9

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  • ミリ波帯電波における温熱知覚閾値の測定

    T. Konno, M. Hanazawa, K. Wake, S. Watanabe, M. Taki, H. Shirai

    Proc. of 2005 IEICE Society Conference   374 - 374   2005.9

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  • 室内伝搬特性に対する壁内部の多重反射の効果について

    R. Sato, H. Sato, H. Shirai

    Proc. of 2005 IEICE Society Conference   "S - 9"-"S-10"   2005.9

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  • Impact of the Gain/Phase Imbalance Between I and Q Channels for the DPC-OF/TDMA System Reviewed

    Kazuyuki Shimezawa, Hiroshi Harada, Hiroshi Shirai

    WPMC2005   TA28-7   VII-940 - VII-944   2005.9

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  • Application of a MoM/FDTD-hybrid method to scattering problems including complex-shape antennas Reviewed

    S. Watanabe, S. Mochizuki, H. Shirai

    Proc. of EMC Europe Workshop 2005   2005.9

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  • ミリ波帯電波における温熱知覚閾値の測定

    T. Konno, M. Hanazawa, K. Wake, S. Watanabe, M. Taki, H. Shirai

    Proc. of URSI Commission K Workshop   2005.9

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  • Cylindrical target reconstruction using RCS values Reviewed

    H. Shirai

    Proc. of 2005 Progress in Electromagnetics Research Symposium   2005.8

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  • A SBR estimation for indoor wave propagation through dielectric walls Reviewed

    R.Sato, H. Sato, H. Shirai

    Proc. of 2005 IEEE International Symposium on Antennas and Propagation and USNC/URSI National Radio Science Meeting   2005.7

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  • Antenna Measurement for Millimeter-Wave Exposure Setup Reviewed

    M. Hanazawa, T. Konno, R. Kumahara, K. Wake, S. Watanabe, M. Taki, H. Shirai

    Proc. of 2005 Bioelectromagnetics Meeting   2005.6

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  • Frequency Characteristics of Power Absorption and of Temperature Elevation for Human Exposure to Millimeter Wave Reviewed

    T. Konno, M. Hanazawa, K. Wake, S. Watanabe, M. Taki, H. Shirai

    Proc. of 2005 Bioelectromagnetics Meeting   2005.6

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  • 散乱体表面の多角柱近似に基づく曲面推定

    Y. Hiramatsu, H. Shirai, M. Suzuki, F. Hidaka

    IEEJ Technical Meeting on EMT   EMT-05-23 ( 14 )   59 - 64   2005.5

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  • 3次元立体視装置を用いた都市空間中の対話的電磁波伝搬の可視化について

    M. Makino, X. Cao, H. Shirai, S. Shinoda

    IEEJ Technical Report on EMT   EMT-05-24 ( 14 )   65 - 70   2005.5

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  • Return Loss Measurement of a Exposure Setup For Rabbit Eyes at 30GHz Band

    Y. Nakada, T. Konno, R. Kumahara, S. Mochizuki, M. Hanazawa, K. Wake, S. Watanabe, H. Shirai

    Proc. of 2005 IEICE General Conference   2005.3

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  • A Novel Cell-Searching Method of Downlink DPC-OF/TDMA

    M. Koshimizu, M. Kamiyama, R. Funada, H. Harada, H. Shirai

    Proc. of 2005 IEICE General Conference   2005.3

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  • Estimation of curved surfaces of polygonal cylinders

    Y. Hiramatsu, M. Suzuki, F. Hidaka, H. Shirai

    Proc. of 2005 IEICE General Conference   2005.3

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  • A study on indoor EM wave propagation by using ray tracing method

    H. Sato, R. Sato, H. Shirai

    Proc. of 2005 IEICE General Conference   2005.3

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  • Development of a Millimeter-Wave Exposure Setup with a Lens Antenna

    T. Konno, R. Kumahara, M. Hanazawa, K. Wake, S. Watanabe, R. Tokunaga, Y. Suzuki, M. Taki, H. Shirai

    IEICE Technical Report on EMC   EMCJ-2005-23 ( 562 )   77 - 82   2005.1

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    We have implemented development of millimeter-wave exposure setups for studies on thresholds of biological effects due to millimeter-wave exposure. In developing the previous setups we have used the circular horn antenna, but the beam radiated from the antenna is difficult to illuminate only the object because of widely broadened propagation characteristics. Therefore we have developed two new setups that realize intended exposure. These setups use different-characteristics lens antennas. In this report measurement of incident power density and of reflection loss are described. Consequently we have confirmed that 1000 mW/cm^2 and 2800 mW/cm^2 of incident power density can be available for these setups with 1 W input which is enough performance for the biological studies.

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  • A study on FDTD cell size for analyzing human head exposure to near EM field

    J. Ohisa, H. Shirai, S. Mochizuki

    IEEJ Technical Report on EMT   EMT-05-10 ( 1 )   53 - 58   2005.1

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  • Sampling Frequency Selection Scheme in Undersampling Systems

    N. Sahara, Y. Kunisawa, H. Iwai, H. Shirai

    IEICE Technical Meeting on Wireless Communication System   RCS-2004-251 ( 597 )   91 - 96   2005.1

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    In software defined radio systems, it is desired to place the analog-to-digital converter (ADC) near the antenna part in the block diagram of the receiver, to improve the flexibility of the system. The radio frequency (RF) sampling method, in which the received signal is sampled at RF stage, realizes such structure. The RF sampling using the undersampling is a potential method to sample the RF signal using the existing consumer ADCs because the high speed ADC is required in the traditional methods, such as the nyquist sampling or the oversampling of the RF signal. This paper presents a technique to determine the minimum sampling frequency to undersample the separated multiple wireless systems simultaneously. In addition, this paper proposes a frequency selecting scheme which enables to select lower sampling frequency by receiving at least the desired transmission channels in the wireless system signals. This paper also provides the estimation of proposed scheme.

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  • Electromagnetic Wave Propagation Analysis for a Simplified Indoor Model by Using Ray Tracing Method

    R. Sato, H. Sato, H. Shirai

    IEEJ Technical Report on EMT   EMT-05-08   41 - 46   2005.1

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  • A SBR algorithm for simple indoor propagation estimation Reviewed

    R Sato, H Sato, H Shirai

    2005 IEEE/ACES International Conference on Wireless Communications and Applied Computational Electromagnetics   810 - 813   2005

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  • ゼロ相互相関特性を有する巡回シフト巡回拡張型符号を用いた符号分割多重伝送

    示沢 寿之, 原田 博司, 白井 宏

    Technical Report of IEICE   RCS2004-211   1 - 6   2004.11

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  • Study on an Undersampling System for Multi-band Receivers Reviewed

    Y. Kunisawa, N. Sahara, H. Shirai, H. Iwai

    Proc. of Global Mobile Congress   2004.10

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  • Performance Evaluation of a CDM Transmission Scheme Based on Sequences with Zero Cross-Correlation Characteristics Reviewed

    Kazuyuki Shimezawa, Hiroshi Harada, Hiroshi Shirai

    WPMC2004   WM6-6   V3-157 - V3-161   2004.9

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  • A new iterative MoM/FDTD formulation for simulating human exposure to electromagnetic waves Reviewed

    S Mochizuki, S Watanabe, M Taki, Y Yamanaka, H Shirai

    IEICE TRANSACTIONS ON ELECTRONICS   E87C ( 9 )   1540 - 1547   2004.9

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    A new hybrid formulation has been derived for analyzing biological electromagnetic compatibility (Bio-EMC) problems by combining the frequency-domain Method of Moments (MoM) and the Finite-Difference Time-Domain (FDTD) method. This hybrid form is different from, and more direct than, the method previously proposed by Mangoud et al. Some numerical examples are given for the human head exposure field due to a half wavelength dipole and a one-wavelength loop antenna. Our iterative method is found to have fast convergence. In addition, our method works well for cases when the radiation antenna wires are not aligned with the FDTD lattice.

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  • A New Co-channel Estimation Method for the Downlink frame of DPC-OF/TDMA Reviewed

    M. Koshimizu, R. Funada, H. Harada, H. Shirai

    Proc. of 60th IEEE Vehicular Technology Conference (VTC2004-fall)   2004.9

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  • On the reconstruction of cylindrical polygonal scatterers with curved surfaces

    M. Suzuki, H. Shirai, Y. Hiramatsu

    IEEJ Technical Report on EMT   EMT-04-89 ( 71 )   99 - 104   2004.9

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  • A simple crack depth estimation method from backscattering response Reviewed

    H Shirai, H Sekiguchi

    IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT   53 ( 4 )   1249 - 1254   2004.8

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    A depth estimation method for a crack on metal surfaces has been studied and a simple estimation formula and measurement method have been proposed. This formula is based on our previous theoretical analysis that the backscattering from a crack causes periodical nulls (dips) as the frequency changes, and the first dip occurs when the depth of the crack becomes nearly one-half the incident wavelength. Dependencies of the crack's aperture and the incident angle have also been studied and considered as our depth estimation parameters. Test measurement has been made to check the validity of our estimation procedure.

    DOI: 10.1109/TIM.2004830789

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  • A new CDM transmission scheme with cyclic shifted-and extended codes and a cancellation technique for accumulated cross-correlation values Reviewed

    K Shimezawa, H Harada, H Shirai

    IEICE TRANSACTIONS ON COMMUNICATIONS   E87B ( 8 )   2212 - 2221   2004.8

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    We have developed a code-division-multiplexing (CDM) transmission scheme for future cellular communication systems, which uses cyclic shifted-and-extended (CSE) codes generated from an M-sequence to enable seamless communication in highly mobile environments. Because the correlation characteristics of CSE codes are determined by the M-sequence, the cross-correlation values are accumulated as a result of combining transmitted signals with opposite polarities in parallel channels. The accumulated cross-correlation values significantly degrade transmission performance, especially with multi-level modulation schemes such as quadrature amplitude modulation (QAM). We thus propose a cancellation technique to eliminate the accumulated cross-correlation values. We have evaluated the transmission performance of the CDM transmission scheme with the proposed technique by computer simulation. The new scheme enables high-quality data transmission in fast-fading channels.

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  • Cylindrical target reconstruction using their frequency and time domain RCS values Reviewed

    H. Shirai, S. Suzuki, K. Ono

    Proc. of 2004 International Symposium on Antennas and Propagation   2004.8

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  • Development of a Millimeter-Wave Exposure Setup for Rabbit Eyes Reviewed

    M. Hanazawa, R. Kumahara, S. Mochizuki, K. Wake, S. Watanabe, M. Taki, Y. Kamimura, Y. Yamanaka, H. Shirai

    Proc. of 2004 Asia-Pacific Radio Science Conference   2004.8

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  • Relevant Measures for Exposure Evaluation in Epidemiological Study

    S. Mochizuki, K. Wake, S. Watanabe, Y. Yamanaka, H. Shirai, M. Taki

    IEICE Technical Report on EMC   EMCJ-2004-37   1 - 4   2004.7

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  • Numerical Techniques of Realistic Modelings and of Large-Scale Simulation for Dosimetry of Human-Body Exposure to Radiofrequency Waves Reviewed

    S. Watanabe, Y. Yamanaka, S. Mochizuki, H. Shirai, Y. Tanaka, M. Takahashi, T. Uno, J. Wang, O. Fujiwara, M. Taki

    Proc. of 2004 IEEE MTT-S International Microwave Symposium   2004.6

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  • 下りリンクDPC-OF/TDMAにおける適応変調のための干渉推定方式に関する一検討

    M. Koshimizu, R. Funada, H. Harada, H. Shirai

    IEICE Technical Report on Wireless Communication System   RCS-06-18 ( 123 )   55 - 60   2004.6

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    In this paper, we propose a new desired signal power to undesired signal power ratio estimation (DURE) method for the downlink frame of dynamic-parameter-controlled orthogonal frequency and time division multiple access (DPC-OF/TDMA) and a new subcarrier arrangement of the orthogonal frequency division multiplexing (OFDM) symbols used for DURE. The proposed subcarrier arrangement enables no interference between the signals transmitted form the adjacent cells by employing orthogonal sequence codes, and thus, we can distinguish the desired signal from the undesired ones and estimate DURE accurately. Moreover, we propose another DURE method. We evaluated the effectiveness of the proposed methods by computer simulation in multi cell environment.

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  • 60GHz帯家兎眼ばく露装置の近傍界特性

    R. Kumahara, S. Mochizuki, M. Hanazawa, K. Wake, S. Watanabe, M. Taki, Y. Kamimura, H. Shirai

    IEICE Technical Report on EMC   EMCJ-2004-23 ( 150 )   53 - 60   2004.6

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    Near-field of a 60-GHz milimeter-wave exposure setup has been measured for developing the exposure system designed to survey the ocular effects of milimeter-wave. To investigate the limited effects of an eye, an antenna and irradiation interval which enable the uniform and local exposure have been examined based on the experimental results. The results show that the circular antenna (QUINSTAR : QWH-VCRROO) exposes relatively uniform and local. Therefore it was confirmed that the exposure to the rabbit eye was uniform and local by setting it 2-3cm away from the antenna.

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  • A fundamental study of warmth sensation produced by millimeter-wave exposure

    T. Konno, S. Mochizuki, M. Hanazawa, K. Wake, S. Watanabe, M, Taki, H. Shirai

    IEICE Technical Report on EMC   EMCJ-2004-24   61 - 66   2004.6

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  • Validation of exposure evaluation based on numerical simulations for cellular-phone epidemiological study Reviewed

    S. Mochizuki, S. Watanabe, M. Taki, Y. Yamanaka, H. Shirai

    Proc. of International Non-Ionizing Radiation Workshop & Symposium   2004.5

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  • A new hybrid MoM/FDTD method for antennas located off the Yee's lattice Reviewed

    S. Mochizuki, S. Watanabe, M. Taki, Y. Yamanaka, H. Shirai

    Proc. of 2004 URSI International Symposium on Electromagnetic Theory   2004.5

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  • Size of Head Phantoms for Standard Measurements of SAR Due to Wireless Communication Devices Reviewed

    Shoji Mochizuki, Soichi Watanabe, Masao Taki, Yukio Yamanaka, Hiroshi Shirai

    Electronics and Communications in Japan, Part I: Communications (English translation of Denshi Tsushin Gakkai Ronbunshi)   87 ( 4 )   82 - 91   2004.4

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    In recent years, a project on the standardization of measurement methods for the head specific absorption rate (SAR) while using cellular phones has been in progress in Japan, Europe, and the United States. In order to achieve international coordination, it is desirable that head phantoms of the same shape be used in all countries
    these are based on statistical data on European and American human sizes. However, the validity of application to the Japanese standard head phantoms which are generally of a larger size than the Japanese human size has not been established. Consequently, SAR measurements are made in this study with head phantoms based on the 90th-percentile values of the head shape statistics of Europeans and Americans (E/A) and head phantoms based on the average Japanese adult male head shape (JP) in order to investigate the dependence of the head SAR on the phantom size. A numerical simulation is also performed, and the effect of the head phantom size on the current distribution on a cellular phone is also investigated. Based on these studies, it is found that the effect of the head phantom characteristics on the head SAR is small compared to the effect of the position of the cellular phone in the measurements, and that the effect on the current distribution on the cellular phone is also small. It is shown that for all three types of cellular phone models, that is, thick, thin, and folding types, that the E/A phantoms have roughly the same or larger maximum local SAR values than the JP phantoms. © 2003 Wiley Periodicals, Inc.

    DOI: 10.1002/ecja.10083

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  • Numerical hybrid analysis method for simulating human exposure to near field of sources

    S. Mochizuki, S. Watanabe, M. Taki, Y. Yamanaka, H. Shirai

    IEEJ Technical Report on EMC   EMC-04-38   35 - 40   2004.4

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  • Frequency and Time Windowing Process for Isolating the RCS Target Spectra Reviewed

    H. Sekiguchi, H. Shirai

    Proc. of 8th Sino - Japan Joint Meeting on Optical Fiber Science and Electromagnetic Theory   313 - 318   2004.3

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  • Target Reconstruction of Convex Cylindrical Scatterers Using Their Monostatic RCS Reviewed

    K. Ono, H. Shirai, S. Aritake

    IEICE Trans. on Electronics   J87-C ( 3 )   296 - 302   2004.3

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  • ミリ波帯電波伝搬特性に対する自動車の影響について

    H.Wakabayashi, T. Mori, T. Yamamoto, H. Shirai, K. Ogawa, K. Sato, M. Fujise, T. Horimatsu

    Proc. of 2004 IEICE General Conference   2004.3

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  • アンダーサンプリング型受信機におけるアンプリングジッタに関する考察

    N. Sahara, Y. Kunisawa, M. Iwai, H. Shirai

    Proc. of 2004 IEICE General Conference   2004.3

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  • 下りリンクDPC-OF/TDMAにおける干渉推定方式に関する一検討

    M. Kosimizu, R. Funada, H. Harada, H. Shirai

    Proc. of 2004 IEICE General Conference   2004.3

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  • 誘電体平板間の電波伝搬特性に関する一考察

    R, Sato, H. Shirai

    Proc. of 2004 IEICE General Conference   2004.3

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  • 60GHz家兎眼ばく露装置のリターンロス特性

    R. Kumahara, S. Mochizuki, M. Hanazawa, K. Wake, S. Watanabe, Y. Yamanaka, M. Taki, Y. Kamimura, H. Shirai

    Proc. of 2004 IEICE General Conference   368   368 - 368   2004.3

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  • 線状ループアンテナへのMoM-FDTD混成法適用に関する検討

    S. Mochizuki, S. Watanabe, M. Taki, Y. Yamanaka, H. Shirai

    Proc. of 2004 IEICE General Conference   387 - 387   2004.3

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  • マルチバンド受信機におけるアンダーサンプリングの一検討

    Y. Kunisawa, N. Sahara, M. Iwai, H. Shirai

    Proc. of IEICE Workshop on Mobile Communication   2004.3

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  • Cyclic shifted-and-extended codes based on almost perfect autocorrelation sequences for CDM transmission scheme Reviewed

    Kazuyuki Shimezawa, Hiroshi Harada, Hiroshi Shirai

    2004 IEEE 60th Vehicular Technology Conference, VTC2004-Fall, VOLS 1-7   5087 - 5091   2004

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    For future cellular communication systems, we have developed a code-division-multiplexing (CDM) transmission scheme based on cyclic shifted-and-extended (CSE) codes generated from a basic code with superior auto-correlation characteristics in order to realize seamless communication in high-speed mobile environment. In this paper, an almost perfect auto-correlation sequence is used as the basic code, and its autocorrelation values are zero except at zero and middle shifts. Moreover. we propose an elimination technique for interference caused by the correlation value at the middle shift. The proposed technique can realize perfect correlation characteristics within the cyclical shifted chips by adding a simple calculation at a receiver. The proposed scheme is evaluated by computer simulations in terms of the bit-error-rate performance for various code lengths of the basic code.

    DOI: 10.1109/VETECF.2004.1405068

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  • Radio wave propagation analysis for a simple indoor model Reviewed

    R Sato, H Shirai

    IEEE ANTENNAS AND PROPAGATION SOCIETY SYMPOSIUM, VOLS 1-4 2004, DIGEST   1648 - 1651   2004

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  • A new iterative MoM/FDTD analysis for EM scattering by a loop antenna Reviewed

    S Mochizuki, S Watanabe, M Taki, Y Yamanaka, H Shirai

    IEEE ANTENNAS AND PROPAGATION SOCIETY SYMPOSIUM, VOLS 1-4 2004, DIGEST   1495 - 1498   2004

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  • An adaptive beam division for a visual simulation of high frequency electromagnetic wave propagation Reviewed

    XY Cao, M Makino, H Shirai, S Shinoda

    2004 JOINT CONFERENCE OF THE 10TH ASIA-PACIFIC CONFERENCE ON COMMUNICATIONS AND THE 5TH INTERNATIONAL SYMPOSIUM ON MULTI-DIMENSIONAL MOBILE COMMUNICATIONS, VOLS 1 AND 2, PROCEEDINGS   710 - 714   2004

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    In this paper, we propose an adaptive beam division method for a visual simulation of high frequency electromagnetic wave propagation. In order to guarantee the correctness of visualization and calculate electromagnetic wave power within beam (transformation from beam data to, volume data) with low computational cost, an adaptive beam division technique is introduced into the beam data structure. By implementation of the proposed method, one can transform beam, data to volume data more correctly with lower computational cost and visualize the high frequency electromagnetic wave propagation by a so-called ray-casting algorithm, which is one of the most useful methods in computer graphics.

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  • Electromagnetic scattering analysis for crack depth estimation Reviewed

    H Sekiguchi, H Shirai

    IEICE TRANSACTIONS ON ELECTRONICS   E86C ( 11 )   2224 - 2229   2003.11

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    A simple non-destructive depth estimation method for a crack on a metal surface has been proposed. This method is based on our finding that the electromagnetic back scattering from a narrow trough (crack model) on the ground plane causes periodical nulls (dips) as the frequency changes, and the first dip occurs when the depth of the crack becomes nearly one half of the incident wavelength. Dependencies of the crack's aperture and the incident angle have also been studied from rigorous and numerical analyses, and considered as our depth estimation parameters. A simple estimation formula for a crack depth has been derived from these studies. Test measurement has been made to check the accuracy of our estimation formula. Time domain gating process is utilized for isolating the crack scattering spectra buried in the measured frequency RCS data. Tested crack types are a. narrow rectangular, a tapered, and a stair approximated crack shapes. It is found that the depth of these cracks can be measured within 3 percent error by our estimation method.

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  • IEICE Science Laboratories for Kids

    Mitsunori Makino, Seiko Ido, Hiroshi Shirai

    IEICE Journal   86 ( 11 )   878 - 883   2003.11

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  • Numerical Analysis of Electromagnetic Interference of A Cardiac Pacemaker in Realistic Voxel Models of Japanese Adult Male and Female Reviewed

    R. Kumahara, S. Mochizuki, S. Watanabe, M. Hanazawa, Y. Yamanaka, H. Shirai

    Proc. of 6th International Congress of the European Bioelectromagnetics Association   2003.11

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  • 3次元空間における電磁波伝搬の可視化について

    H. Sekiguchi, J. Ohisa, H. Shirai

    IEEJ Technical Report on EMT   EMt-03-53   2003.11

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  • Performance Evaluation of a New CDM Transmission Scheme with CSE Codes and Cross-Correlation Cancellation Technique in Fast Multipath Fading Channel Reviewed

    K. Shimezawa, H. Harada, H. Shirai

    Proc. of 6th International Symposium on Wireless Personal Multimedia Communications (WPMC '03)   2003.10

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  • Crack depth estimation by back scattering response Reviewed

    H. Sekiguchi, H. Shirai

    Proc. of 2003 IEEE Topical Conference on Wireless Communication Technology   2003.10

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  • A CDM Transmission Scheme with Cancellation Technique for Accumulated Cross-Correlation Values Reviewed

    K. Shimezawa, H. Harada, H. Shirai

    Proc. of 2003 Vehicular Technology Conference (VTC2003-fall)   2003.10

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  • ミリ波帯電波の人体入射時における電力吸収特性

    T. Konno, S. Michizuki, R. Kumahara, M. Hanazawa, K. Wake, S. Watanabe, Y. Yamanaka, H. Shirai

    Proc. of 2003 IEICE Society Conference   2003.9

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  • 任意の方向に配置された線状アンテナへのMoM-FDTD混成法適用に関する検討

    S. Michizuki, S. Watanabe, M.Taki, Y. Yamanaka, H. Shirai

    Proc. of 2003 IEICE Society Conference   2003.9

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  • 高速適応変調方式を用いたOFDM/TDD移動無線通信システムに関する一検討

    小清水 克, 示沢寿之, 白井 宏, 原田博司

    電子情報通信学会 ソサエティ大会   B-5-69   2003.9

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  • CDMを用いたワイヤレスアクセスシステムにおける相互相関低減方法に関する一検討

    示沢寿之, 原田博司, 白井 宏

    電子情報通信学会 ソサエティ大会   B-5-36   2003.9

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  • Higher order terms of high frequency asymptotic series Reviewed

    Hiroshi Shirai

    IEICE Trans. on Communications   J86-B ( 9 )   1776 - 1776   2003.9

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  • 後方散乱を用いたテーパー型クラックの深さ推定

    H. Sekiguchi, H. Shirai

    Prof. of 2003 IEICE Society Conference   2003.9

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  • ミリ波帯用ばく露装置開発のための基礎検討

    R. Kumahara, S. Mochizuki, K. Wake, M. Hanazawa, Y. Yamanaka, H. Shirai

    Proc. of 2003 IEICE Society Conferece   2003.9

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  • An Interactive Visualization of High Frequency Electromagnetic Wave Propagation on the CAVE Reviewed

    X. Cao, M. Makino, H. Shirai, S. Shinoda

    Proc. of The 3rd CAVE-Programming Workshop   2003.8

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  • 断面形状が異なるクラックの深さ推定とその誤差についての検討

    H. Sekiguchi, H. Shirai

    IEEJ Technical Meeting on EMT   EMT-03-27   2003.7

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  • A simple estimation formula for a crack depth using the RCS dip Reviewed

    H. Sekiguchi, H. Shirai

    Proc. of 2003 IEEE International Symposium on Antennas and Propagation   2003.6

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  • Simplified Analysis of Indoor Radio Wave Propagation At 2.4GHz Band Reviewed

    R. Sato, K. Hayashi, Hiroshi Shirai

    Proc. of 2003 IEEE International Symposium on Antennas and Propagation   2003.6

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  • 日本人数値人体モデルを用いた携帯電話の心臓ペースメーカ影響評価に関する検討

    R. Kumahara, S. Mochizuki, S. Watanabe, Y. Yamanaka, H. Shirai

    IEICE Technical Report on EMC   103 ( 101 )   7 - 12   2003.5

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    Electromagnetic interference of implanted pacemakers by mobile telephones has been investigated by FDTD method. An implanted cardiac pacemaker, lead wire and an electrode are modeled in realistic voxel models of Japanese adult male and female which were constructed from MRI images. It is shown that the induced voltage at a connector of the pacemaker in European-American voxel model is higher than those in Japanese models. It is also shown that the induced voltage for the Japanese male model is higher than that of Japanese female model. Furthermore, it is shown that the induced voltage evaluated by an experimental method using homogeneouse recutangular model is higer than those of the human models, that is the rectangular model provides the most safety estimation.

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  • A simple crack depth estimation method by using monostatic RCS Reviewed

    Hiroshi Shirai, H. Sekiguchi

    Proc. of 2003 IEEE Instrumentation & Measurement Technology Conference   1143 - 1146   2003.5

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  • High frequency scattering simulation using asymptotic solution

    Hiroshi Shirai

    Proc. of IEICE 7th Microwave Simulator Workshop   28 - 34   2003.3

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  • A crack depth estimation error using the time domain gating method

    Hidenori Sekiguchi, Hiroshi Shirai

    Proc. of 2003 IEICE General Conference   5   2003.3

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  • A Hybrid MoM-FDTD Analysis of SAR in Human Head Models Near a Dipole Antenna

    Shoji Mochizuki, Soichi Watanabe, Masao Taki, Yukio Yamanaka, Hiroshi Shirai

    Proc. of 2003 IEICE General Conference   B-4   2003.3

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  • A study on indoor radio wave propagation modeling at 2.4GHz band

    Ryoichi Sato, Kei Hayashi, Hiroshi Shirai

    Proc. of 2003 IEICE General Conference   C-1-13   13   2003.3

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  • Filtering Process of Electromagnetic Scattering Response Using Wavelet Analysis

    Tomokazu Mori, Hiroshi Shirai

    2003 IEICE General Conference   C-1-21   21   2003.3

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  • A proposal of overfill CDM transmission scheme for future road-vehicle communication systems Reviewed

    K Shimezawa, H Harada, H Shirai, M Fujise

    IEICE TRANSACTIONS ON COMMUNICATIONS   E86B ( 1 )   68 - 78   2003.1

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    In order to realize a future seamless high-speed road-vehicle communication system, we have proposed using code division multiplexing (CDM) radio transmission scheme by using cyclic shifted-and-extended (CSE) codes as spread codes. As the CSE codes are generated by cyclically shifting and extending a conventionally used code, the number of codes generated from a code is limited to the length of the shift interval and the tolerable period of delayed waves also depends on the length. In this paper, based on CSE codes, we propose a method to minimize the length of the shift interval and a cancellation technique with a simple calculation in order to eliminate the interference from delayed waves caused by the reduction of the length of shift interval. The concept and the BER performances in AWGN, two-paths, and multi-path fading environments are described in this paper. As a result, the maximum transmission rate of CSE-based-CDM transmission per one-code using the newly proposed transmission scheme is 3 times as large as that using conventional CSE codes and DQPSK-CDM transmission scheme.

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  • Crack depth estimation algorithm from RCS returns Reviewed

    Hidenori Sekiguchi, Hiroshi Shirai

    Proc. of 2003 Progress in Electromagnetics Research Symposium (PIERS 2003)   2003.1

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  • Reconstruction algorithm for convex polygonal objects using RCS values Reviewed

    Kenji Ono, Hiroshi Shirai, Mitsunori Makino, Junhi Chao

    Proc. of 2003 Progress in Electromagnetics Research Symposium (PIERS 2003)   2003.1

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  • Application of Hybrid MoM-FDTD Method to Problems of Biological Electromagnetic Compatibility

    Shoji Mochizuki, Soichi Watanabe, Masao Taki, Yukio Yamanaka, Hiroshi Shirai

    IEICE Technical Report on EMC   EMCJ-2002-101 ( 1 )   31 - 37   2003.1

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  • Simplified analysis for indoor propagation of a WLAN channel Reviewed

    R Sato, H Shirai

    2003 IEEE TOPICAL CONFERENCE ON WIRELESS COMMUNICATION TECHNOLOGY   248 - 249   2003

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  • Novel iteration procedures of a hybrid method combining MoM and scattered-field FDTD method for electromagnetic dosimetry Reviewed

    S Mochizuki, S Watanabe, M Taki, Y Yamanaka, H Shirai

    2003 IEEE TOPICAL CONFERENCE ON WIRELESS COMMUNICATION TECHNOLOGY   200 - 201   2003

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  • Electromagnetic wave propagation measurement in an urban environment

    Hironobu Ohkubo, Taisuke Nakanishi, Hiroshi Shirai

    IEEJ Technical Report on EMT   EMT-02-75   83 - 88   2002.10

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  • A crack depth estimation by using monostatic RCS

    Hidenori Sekiguchi, Hiroshi Shirai, Ryoichi Sato

    IEEJ Technical Report on EMT   EMT-02-67   35 - 40   2002.10

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  • Recognition of cylindrical scatterers using their RCS values I -Evaluation in frequency domain-

    Kenji Ono, Tomoyuki Aizawa, Hiroshi Shirai

    IEICE Technical Report on EMT   EMT-02-92   1 - 6   2002.10

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  • Recognition of cylindrical scatterers using their RCS values II -Evaluation in time domain-

    Shinjirou Suzuki, Kenji Ono, Hiroshi Shirai

    IEEJ Technical Report on EMT   EMT-02-93   7 - 12   2002.10

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  • High frequency EM scattering analyses by automobile models

    Hiroshi Shirai

    Proc. of 2002 IEICE Society Conference   299 - 300   2002.9

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  • Detail dosimetric asessment of a human head exposed to near-field of various sources using advanced numerical hybrid techniques Reviewed

    Shoji Mochizuki, Soichi Watanabe, Kanako Wake, Masao Taki, Yukio Yamanaka, Hiroshi Shirai

    Proc. of URSI XXVII-th General Assembly   2002.8

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  • Radio wave propagation inside two adjacent partially dielectric loaded trough Reviewed

    Roichi Sato, Hiroshi Shirai

    Proc. of URSI XXVII-th General Assembly   2002.8

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  • 近傍波源の近傍界特性と人体内電磁界分布との関係

    S. Mochizuki, S. Watanabe, K. Wake, M. Taki, Y. Yamanaka, H. Shirai

    IEICE Technical Report on EMC   EMCJ-2002-70 ( 210 )   1 - 5   2002.7

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    The dose characteristics in a human head exposed to the near field of various fundamental sources have been evaluated numerically by the finite-difference time-domain (FDTD) method. It is shown that the electromagnetic fields in the human head strongly depend on the near-field characteristics of the sources. In the case of the infinitesimal short electric dipole, it is also suggested that the internal E- and H-field as well as current density and SAR are closely related with the incident H-field.

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  • An adaptive beam tracing for visual simulation of ray propagation in wirreless communication systems Reviewed

    Mitsunori Makino, Xiaoyi Cao, Hiroshi Shirai, Shoji Shinoda, Kenji Kawakita

    Proc. of The International Technical Conference on Circuits/Systems, Computers and Communications   2002.7

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  • 後方散乱断面積を用いたクラックの深さ推定

    H. Sekiguchi, H. Shirai, R. Sato

    IEEJ Technical Report on EMT   EMT-02-54   7 - 12   2002.7

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  • Experimental crack depth estimation by EM Waves Reviewed

    Hidenori Sekiguchi, Hiroshi Shirai, Ryoichi Sato

    Proc. of 2002 IEEE AP-S Intenational Symposium and USNC/URSI National Radio Science URSI Meeting   2002.6

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  • Overfill CDMを用いたDSRCシステムの高速伝送化に関する一検討

    示沢 寿之, 原田 博司, 白井 宏, 藤瀬 雅行

    Technical Report of IEICE   ITS2002-3   13 - 18   2002.5

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  • The Size of Head Phantoms for the Standard Measurement Methods of SAR Due to Wireless Communication Devices Reviewed

    Shoji mochizuki, Soichi Watanabe, Hiroshi Shirai, Masao Taki, Yamanaka Yukio

    IEICE Trans. on Communications   J85-B ( 5 )   640 - 648   2002.5

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    最近,我が国をはじめ欧米諸国では携帯電話使用時の頭部SAR測定法の標準化作 業が進められており,国際的な整合性を図るために,各国で欧米人体型寸法統計データ に基づいた同一形状の頭部ファントムを使用することが求められている. しかし,日本人と比べて全体的な形状が大きい標準頭部ファントムを日本 人に適用することの妥当性は十分に示されていない. そこで,本研究では,欧米人の頭部形状統計データの90パーセンタイル値に基づく頭部ファントム(E/A)と平均的な日本人成人男性頭部形状に基づく頭部ファントム(JP)を用いたSAR測定を行ない,頭部SARのファントムサイズへの依存性について検討を行なった.

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  • A study of the crack depth estimation on a conducting surface Reviewed

    Hidenori Sekiguchi, Hiroshi Shirai, Ryoichi Sato

    Trans. of IEE Japan   122A ( 12 )   1011 - 1016   2002.4

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    An algorithm to estimate non-destructively the depth of a crack has been proposed in this paper using electromagnetic waves. From our theoretical study of the scattering by a trough on a conducting surface, it is found that periodical sharp dips in the scattering return occur as one sweeps the operation frequency, and the first dip frequency corresponds to the crack depth. Based on this observation, corelation curves between the first dip frequency and the crack depth have been made.

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  • ビル屋上に設けられたアンテナからの放射電磁界の可視化

    T. Nakanishi, S. Watanabe, N. Okubo, H. Shirai

    Proc. of 2002 IEICE General Conference   21   2002.3

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  • 窪みを持つ物体からの電磁波散乱

    T. Aizawa, H. Shirai

    Proc. of 2002 IEICE General Conference   22   2002.3

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  • 適応SBR法による高周波散乱解析と可視化

    H. Shirai

    Proc. of 2002 IEICE General Conference   402 - 403   2002.3

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  • Dynamic channel filtering processing method for multi-mode & multi-service software radio communciations system Reviewed

    R. Sawai, H. Harada, H. Shirai, M. Fujise

    Proc. of European Wireless 2002   546 - 550   2002.2

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  • 電波伝搬ビジュアル・シミュレーションのための適応ビーム・トレーシングの改良

    J. Cao, M.Makino, H. Shirai, S. Shinoda

    IEICE Technical Report on Circuit and Systems   CAS-2001-98 ( 633 )   1 - 7   2002.1

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    In order to accelerate the previously proposed visual simulation of high frequency electromagnetic wave propagation, a beam tracing method with improved subdivision technique is proposed, in which the beam is defined by three rays. According to reflection of the rays on the buildings or ground, additional rays are generated adaptively and the beam is subdivided automatically with the proposed subdivision algorithm. By using it we can generate the numbers of beams less than ones generated by the previously proposed subdivision technique. After generation of the set of beams, we transform the electromagnetic wave propagation data into volume data. Then one can visualize the data of propagation with interaction at any viewpoints by the so-called ray-casting algorithm, which is one of the most useful methods in computer graphics.

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  • A high-speed DSRC system assisted by an overfill CDM for future seamless road-vehicle communication systems Reviewed

    K Shimezawa, H Harada, H Shirai, M Fujise

    IEEE 56TH VEHICULAR TECHNOLOGY CONFERENCE, VTC FALL 2002, VOLS 1-4, PROCEEDINGS   1307 - 1311   2002

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    In order to realize a future seamless high-speed road-vehicle communication system, we have proposed using code division multiplexing (CDM) radio transmission scheme by using cyclic shifted-and-extended (CSE) codes as spread codes. As the CSE codes are generated by cyclically shifting and extending a conventionally used code, the number of codes generated from a code is limited to the length of the shift interval and the tolerable period of delayed waves also depends on the length. In this paper, based on CSE codes, we propose a method to minimize the length of the shift interval:and a cancellation technique with a simple calculation in order to eliminate the interference from delayed waves caused by the reduction of the length of shift interval. The concept of the proposed scheme and the BER performances in AWGN, two-paths, and multipath fading environment are described in this paper. As a result, the maximum transmission rate of CSE-based-CDM transmission per one-code using the newly proposed transmission scheme is 3 times as large as that using conventional CSE codes and DQPSK-CDM transmission scheme.

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  • レーダ散乱量を用いた散乱体の形状推定についての研究

    H. Shirai, J. Chao, M. Makino

    Proc. of Chuo University TISE Joint Research Meeting   12 - 15   2001.12

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  • マルチモード・マルチサービスソフトウエア無線通信システムのためのサンプリング処理法に関する研究

    R. Sawai, H. Harada, H. Shirai, S. Shinoda

    Proc. of TISE   2001.12

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  • マルチモード・マルチサービスソフトウェア無線通信システムのための動的なチャネル選択フィルタリング処理法に関する一検討

    R. Sawai, H. Harada, H. Shirai, M. Fujise

    IEICE Technical Report on Software Radio   51 - 58   2001.12

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  • PSK-CDM及びQAM-CDMを用いた連続型DSRCシステム

    示沢 寿之, 原田 博司, 白井 宏, 藤瀬 雅行

    情報処理学会研究報告, ITS, [高度交通システム]   2001(109)   37 - 43   2001.11

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  • 頭部ファントムサイズが頭部内SARの計算に及ぼす影響について

    H. Shirai

    IEICE Technical Report on Electromagnetic Phantom   2001.11

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  • 複雑な形状の物体による散乱

    H. Shirai

    IEEJ Technical Report on EMT   2001.10

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  • RCS値を用いた凸型形状散乱体の形状認識について

    K. Ono, H. Shirai, S. Aritake, M. Makino, J. Chao

    IEEJ Technivcal Report on EMT   2001.10

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  • 電磁波を用いた導体平板上のクラック検出に関する一考察

    H. Sekigichi, H. Shirai, R. Sato

    IEEJ Technical Report on EMT   2001.10

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  • An advanced DSRC system based on a code-division-multiplexing based radio transmission scheme Reviewed

    K.Shimezawa, H.Harada, H.Shirai, M.Fujise

    Proc. of The 2nd International Workshop on ITS Telecommunications   77 - 82   2001.10

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  • 符号分割多重伝送方式を用いたDSRCシステムの基礎伝送特性

    示沢寿之, 原田博司, 白井 宏, 藤瀬雅行

    電子情報通信学会 ソサエティ大会   B-5-132   2001.9

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  • Adaptive SBR Algorithm for Site Specific EM Wave Propagation Estimation Reviewed

    S. Watanabe, H. Shirai, M. Makino, S. Shinoda

    Proc. of 2001 Korea-Japan AP/EMC/EMT Joint Conference   94 - 97   2001.9

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  • Effect of Hand Holding a Cellular Phone on the SAR Distribution in the Head Reviewed

    S. Mochizuki, S. Watanabe, M. Taki, Y. Yamanaka, H. Shirai

    Proc. of 2001 Asia-Pasific Radio Science Conference   415   2001.8

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  • Electromagnetic wave scattering Analysis for Detecting Cracks Reviewed

    H.Shirai, R.Sato, H.Sekiguchi

    Proc. of 2001 URSI International Symposium on Electromagnetic Theory   129 - 131   2001.8

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  • Specific Absorption Rates in Head Phantoms of Different Shape and Size for Cellular Telephone Use Reviewed

    S.Watanabe, S.Mochizuki, H.Shirai, M.Taki, Y.Yamanaka

    Proc. of 2001 Asia-Pasific Radio Science Conference   272   2001.8

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  • High frequency EM scattering by automobile models Reviewed

    H.Shirai, K.Okawa, T.Hayashi

    Proc. of 2001 Progress in Electromagnetics Research Symposium   124   2001.7

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  • An adaptive symbol timing synchronization method for multi-mode & multi-service software radio communications system

    R Sawai, H Harada, H Shirai, M Fujise

    IEICE TRANSACTIONS ON COMMUNICATIONS   E84B ( 7 )   1885 - 1896   2001.7

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    A symbol timing synchronization method is proposed for the realization of a multi-mode and multi-service software radio receiver. The method enables an accurate search for the optimum symbol timing without ally redundant hardware such as sampling rate conversion devices. when the system clock is non-integer times for the target systems' symbol rates. Accordingly, a multimode and multi-service receiver can set an arbitrary system clock for the target system's symbol rates, and the number of A/D converters call bo reduced to the minimum. Also, it may lead to a reduction of the implementation time for digital signal processing hardware, and reduce the burden on the memory in a multi-mode and multi-service software radio receiver, since no sampling rate conversion is needed. Thf effectiveness of the proposed method for use with a multi-mode and multi-service software radio receiver for future ITS services. which are CPS (Global Positioning System). ETC (Electric Toll Collection system), and Japanese PHS (Personal Handy-phone System) is assumed, and the supposed system is evaluated by computer simulation. The jitter performance under an AWGN (Additive White Gaussian Noise) environment is first simulated, and the necessary number of over-samples and observation symbols are defined bq the value of jitter which gives a theoretical value of the BER, respectively. Moreover, the bit error rate performance under a fading environment condition where the attenuation of a signal level fluctuates more rapidly than in a noise environment is calculated, and it is shown that the proposed method enables an accurate search for the optimum synchronization timing caused by a cycle slip even if the signal level is quite low, and allows one handset to adopt a system clock for several systems.

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  • An Approximate Scattering Analysis for Detecting Cracks Reviewed

    R.Sato, H.Shirai

    Proc. of 2001 Progress in Electromagnetics Research Symposium   261   261   2001.7

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  • Ray mode coupling analysis at the aperture of open cavities, Reviewed

    H.Shirai

    Proc. of 2001 International Workshop on Advanced Electromagnetics   22   2001.7

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  • Electromagnetic Wave Scattering by Two Rectangular Troughs on a Ground Plane -H Polarization Case- Reviewed

    R,Sato, H.Shirai

    Proc. of 2001 IEEE AP-S Intenational Symposium   4   742 - 745   2001.7

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  • An adaptive multi-sampling processing method for multi-mode & multi-service software radio communications system

    R. Sawai, H. Harada, H. Shirai, M. Fujise

    IEICE Trans. on Commununications   J84-B ( 7 )   1187 - 1197   2001.7

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  • Shooting and Bouncing Ray Algorithm for Site Specfic Electromagnetic Wave Propagation Prediction, Reviewed

    H.Shirai, S.Watanabe, M.Makino, S.Shinoda

    Proc. of 4th international Symposium on Multi-Dimensional Mobile Communications (MDMC'01)   133 - 138   2001.6

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  • A visual simulation of ray propagation in the use of adaptive beam tracing for wireless communications systems Reviewed

    M.Makino, A.Ohsaki, H.Shirai, S.Shinoda

    Proc. of 4th international Symposium on Multi-Dimensional Mobile Communications (MDMC'01)   125 - 132   2001.6

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  • SAR distributions in head phantoms based on the haeds of European-American and Asian (Japanese) people Reviewed

    S.Watanabe, S.Mochizuki, H.Shirai, M.Taki, Y.Yamanaka

    Proc. of 2001 Annual Meeting of Bioelectromagentics   2001.6

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  • 地理情報を用いた都市部における電波伝搬シミュレーション

    H. Shirai, S. Watanabe, M. Makino, S. Shinoda

    第7回 統合型地理情報システムシンポジウム講演録(中央大学理工学研究所)   31 - 34   2001.4

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  • 頭部ファントム形状に対する最大局所SARの依存性に関する検討

    S. Mochizuki, S. Watanabe, M. Taki, Y. Yamanaka, H. Shirai

    Proc. of 2001 IEICE General Conference   388 - 388   2001.3

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  • 適応ビームトレーシングによる高周波電波伝搬のビジュアル・シミュレーション

    A. Osaki, M. Makino, H. Shirai, S. Shinoda

    IEICE Technical Report on Circuit ans Syatems   100(574) ( 574 )   23 - 30   2001.1

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    In order to analyze urban propagation environment of electromagnetic waves, in this paper a beam tracing method with subdivision technique is proposed, in which the beam is generated by a set of three rays. According to reflection of the rays on the buildings and/or ground, additional rays are generated adaptively and the beam is subdivided automatically. After generation of the set of beams, the obtained electromagnetic wave propagation data can be easily transformed into volume data. Then one can visualize the data of propagation with interaction at any viewpoint by the so-called ray casting algorithm, which is one of the most useful methods in computer graphics.

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  • Applicability of impedance boundary condition for approximating a loaded trough on a ground plane

    R Sato, H Shirai

    IEICE TRANSACTIONS ON ELECTRONICS   E84C ( 1 )   123 - 125   2001.1

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    An electromagnetic wave scattering by a material loaded rectangular trough on a ground plane is approximately analyzed by using standard impedance boundary condition (SIBC). The validity of the derived approximate solution is examined by comparing with the rigorous: orle not only for the oblique incidence but also for the variation of both the filled material's parameters and the trough dimension. An applicability condition has been derived here for this trough structure.

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  • A feasibility of an adaptive sampling processing method for software defined radio Reviewed

    R Sawai, H Harada, H Shirai, M Fujise

    IEEE VTC 53RD VEHICULAR TECHNOLOGY CONFERENCE, SPRING 2001, VOLS 1-4, PROCEEDINGS   1892 - 1896   2001

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    A new adaptive sampling processing method is presented in order to integrate several radio communication systems by a system clock effectively. The proposed method can distribute a system clock adaptively for each integrated system by one sampler according to the target systems' symbol/chip rate. As an evaluation of the proposed method, a Multi-mode & Multiservice Software Radio (MMSR) communications system for future intelligent transport systems is designed, and the BER performances under additive white Gaussian noise (AWGN), one path and two-paths Rayleigh fading environments are evaluated by computer simulation.

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  • High frequency analysis of EM scattering by automobile models

    H.Shirai, T.Hayashi, K.Okawa

    Proc. of 2000 Optical Fiber Science and Electromagnetic Theory   255 - 258   2000.12

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  • Adaptive sampling processing method for multi-mode & multi-service software radio communications system

    R.Sawai, H.Harada, H.Shirai, M.Fujise

    Proc. of the 1st Workshop on ITS Telecommunications-ITST2000   245 - 250   2000.10

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  • マルチモード・マルチサービスソフトウェア無線通信システムのための適応マルチサンプリング処理法に関する一検討

    R. Sawai, H. Harada, H. Shirai, M. Fujise

    IEICE Technical Report on Sofware Radio   75 - 82   2000.10

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  • 都市空間における電磁波伝搬解析と可視化について(2)

    S. Watanabe, H. Shirai, M. Makino

    IEEJ Technical Report on EMT   EMT-00-73   45 - 50   2000.10

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  • 導体平板上の二つの方形溝による平面電磁波の散乱-H偏波の場合-

    R. Sato, H. Shirai

    IEEJ Technical Report on EMT   EMT-00-98   1 - 6   2000.10

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  • マルチモード・マルチサービスソフトウェア無線のための適応マルチサンプリング処理に関する一検討

    澤井亮, 原田博司, 白井宏, 藤瀬雅行

    電子情報通信学会 ソサエティ大会   B-5-17   2000.9

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  • IBC's applicability for approximating a loaded rectangular trough

    R.Sato, H.Shirai

    Proc. of 2000 International Symposium on Antennas and Propagation   Ⅰ   81 - 84   2000.8

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  • RCS analysis of plane wave scattering by finite parallel plate waveguide cavities

    H.Shirai, K.Watanabe

    Proc. of 2000 International Symposium on Antennas,Propagation,and EM Theory   451 - 454   2000.8

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  • EM plane wave scattering by cracks

    H.Shirai, R.Sato

    Proc. of 2000 Progress in Electoromagnetics Research Symposium   1150   2000.7

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  • 3次元空間における電波伝搬ビジュアル・シミュレーション

    A. Osaki, M. Makino, H. Shirai, S. Shinoda

    Proc. of 19th Simulation Technology Conference   2000   173 - 176   2000.6

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  • マルチモード・マルチサービスソフトウェア無線通信システムのための適応シンボルタイミング同期法に関する一検討

    R. Sawai, H. Harada, H. Shirai, M. Fujise

    IEICE Technical Report on Software Radio   SR-00-04   25 - 32   2000.4

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  • CG技法を援用した移動体通信基地局配置支援

    M. Makino, A. Osaki, H. Shirai, S. Shinoda

    第5回統合型地理情報システムシンポジウム論文集   25 - 31   2000.4

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  • マルチサービス・マルチモードソフトウェア無線機のための適応シンボルタイミング同期法

    澤井 亮, 原田博司, 白井 宏, 藤瀬雅行

    電子情報通信学会 総合大会   B- 5-101   2000.3

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  • 自動車モデルによるレーダ散乱断面積

    K. Okawa, H. Shirai, T. Hayashi

    Proc. of 2000 IEICE General Conference   21   2000.3

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  • 地理情報に基づいた電磁波伝搬の可視化

    T. Yano, K. Hashiguchi, H. Shirai, M. Makino, S. Shinoda

    Proc. of 2000 IEICE General Conference   21 - 21   2000.3

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  • Adaptive symbol timing synchronization method based on maximum likelihood estimation for the realization of multi-mode & multi-service software radio

    R Sawai, H Harada, H Shirai, M Fujise

    2000 IEEE 51ST VEHICULAR TECHNOLOGY CONFERENCE, PROCEEDINGS, VOLS 1-3   2   1276 - 1280   2000

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    This paper newly proposes an adaptive symbol timing synchronization method based on maximum likelihood estimation for the realization of multi-mode & multi-service software radio, which is possible to search accurately for the optimum symbol timing from digitally over-sampled signal without the rate conversion circuit when the system clock rate is non-integer times of the symbol rate for the received system. Thus we can realize multi-mode & multi-service software radio by minimum number of signal processing components like AID converter. Finally, we suppose the triple-mode receiver for ITS, which are Japanese Personal Handy-phone System (PHS), Electric Toll Collection (ETC) and Global Positioning System (GPS), and evaluate the jitter performance and bit error rate performance by computer simulation.

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  • Electromagnetic wave scattering by two rectangular troughs on a ground plane

    R Sato, H Shirai

    IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM, VOLS 1-4   Ⅰ   418 - 421   2000

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  • Plane wave scattering by staggered parallel plate waveguide cavities

    H Shirai, K Watanabe

    2000 5TH INTERNATIONAL SYMPOSIUM ON ANTENNAS, PROPAGATION AND EM THEORY PROCEEDINGS   451 - 454   2000

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  • 自動車モデルに対する電磁波の散乱

    H. Shirai, T. Hayashi

    IEEJ Technical Report on EMT   EMT-99-78   47 - 52   1999.11

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  • Plane wave scattering with multiple diffraction by finite parallel plate waveguide cavities

    H. Shirai, K. Watanabe, N. Hasegawa, H. Sekiguchi

    IEICE Trans. on Eletronics   J82-C-1 ( 11 )   625 - 632   1999.11

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  • A beam tracing method of ray propagation for wireless communication systems,

    M.Makino, A.Ohsaki, H.Shirai, S.Shinoda

    Proc. of 1999 Internaational Symposium on Nonlinear Theory and its Applications (NOLTA'99)   2   891 - 894   1999.11

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  • 都市空間における電磁波伝搬解析と可視化について

    K. Hahiguchi, T. Yano, H. Shirai, M. Makino

    IEEJ Technical Report on EMT   EMT-99-74   19 - 24   1999.11

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  • 導体平板上の二つの方形溝による平面電磁波の散乱

    R, Sato, H. Shirai

    IEEJ Technical Report on EMT   EMT-99-123 ( 122 )   7 - 11   1999.11

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  • 地理情報に基づいた電波伝搬の予測について

    H. Shirai, M. Makino, S. Shinoda, K. Hashiguchi, T. Yano

    第4回統合型地理情報システムシンポジウム講演録(中央大学理工学研究所)   43 - 48   1999.11

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  • 携帯電話使用時の頭部内SARに対する耳翼影響

    H. Wakabayashi, S. Watanabe, M. Taki, Y. Yamanaka, H. Shirai

    IEEJ Technical Report on EMT   EMT-99-76 ( 71 )   31 - 40   1999.11

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  • General purpose symbol rate and symbol timing estimation method by using multi-resolution analysis besed on wavelet transform for multimode software radio

    R.Sawai, H.Harada, H.Shirai, M.Fujise

    Proc. of IEEE Vehicular Technology Conference (VTC) 1999   2128 - 2132   1999.9

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    DOI: 10.1109/vetecf.1999.797314

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  • EM wave scattering by cracks

    R.Sato, H.Shirai

    Proc. of XXXVI-th General Assembly of Internationl Union of Radio Science,   p.B3.15   B3.15   1999.8

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  • The peak specific absorption rate in a human head that has an ear lobe exposed to microwave from a cellular telephone

    S.Watanabe, H.Wakayanagi, T.Hamada, M.Taki, Y.Yamada, H.Shirai

    Proc. of XXXVI-th General Assembly of Internationl Union of Radio Science,   p.KA.6   KA.6   1999.8

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  • A visual simulation for high frequency electromagnetic wave propagation

    A.Ohsaki, M.Makino, H.Shirai, S.Shinoda

    Proc. of The 1999 International Technical Conference on Circuits/Systems,Computer and Communications,   1   229 - 232   1999.7

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  • The location of the peak SAR in a human head with an earlobe exposed to microwave from a cellular telephone

    S.Watanabe, H.Wakayanagi, T.Hamada, M.Taki, Y.Yamanaka, H.Shirai

    Proc. of 21st Annual Meeting of Bioelectromagentics   248 - 249   1999.6

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  • An experimental study on the dependence of local SARS on a human ear during exposure to MW from a cellular telephone

    S.Watanabe, H.Wakayanagi, T.Hamada, M.Taki, Y.Yamanaka, H.Shirai

    Proc. of 1999 International Syposium on Electromagentic Compatibility   341 - 344   1999.5

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  • 都市空間のボリュームデータ化に関する検討

    M. Makino, H. Shirai, S. Shinoda, A. Osaki, T. Sano

    第3回統合型地理情報システムシンポジウム講演録(中央大学理工学研究所)   19 - 22   1999.4

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  • 携帯電話によるMW曝露時における人体局所SARのピーク値に対する耳翼の影響に関する実験的検討

    H. Wakayanagi, T. Hamada, S. Watanabe, M. Taki, H. Shirai, Y. Yamanaka

    Proc. of 1999 IEICE General Conference   293   1999.3

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  • High frequency propagation prediction and estimation for wireless communication systems

    H Shirai

    1999 IEEE MTT-S SYMPOSIUM ON TECHNOLOGIES FOR WIRELESS APPLICATIONS DIGEST   117 - 120   1999

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    Proper site choice of base stations is important for establishing a stable and secure wireless communication channel. Accordingly, propagation prediction method, which can be easily implemented for high frequency wireless communication channel in urban environment should be developed. In this paper! basic idea of ray tracing technique to account for reflection and diffraction from ground and surrounding building structure will be discussed for propagation prediction in ur ban environment.

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  • A visual simulation of ray propagation for wireless communication systems

    M. Makino, A. Ohsaki, S. Shinoda, H. Shirai

    IEEE Region 10 Annual International Conference, Proceedings/TENCON   1   534 - 537   1999

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    In order to analyze the urban propagation environment of electromagnetic waves, we propose a beam tracing method with a subdivision technique, in which the beam is generated by three rays. According to reflection of the rays on the buildings or ground, additional rays are generated adaptively and the beam is subdivided automatically. After generation of the set of beams, we transform the electromagnetic wave propagation data into volume data. Then one can visualize the data of propagation at any viewpoint by the so-called ray casting algorithm, which is one of the most useful methods in computer graphics.

    DOI: 10.1109/TENCON.1999.818469

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  • A visual simulation of ray propagation for wireless communication systems

    M. Makino, A. Ohsaki, S. Shinoda, H. Shirai

    IEEE Region 10 Annual International Conference, Proceedings/TENCON   1   534 - 537   1999

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    In order to analyze the urban propagation environment of electromagnetic waves, we propose a beam tracing method with a subdivision technique, in which the beam is generated by three rays. According to reflection of the rays on the buildings or ground, additional rays are generated adaptively and the beam is subdivided automatically. After generation of the set of beams, we transform the electromagnetic wave propagation data into volume data. Then one can visualize the data of propagation at any viewpoint by the so-called ray casting algorithm, which is one of the most useful methods in computer graphics.

    DOI: 10.1109/TENCON.1999.818469

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  • EM scattering analysis by a loaded trough on a ground plane using SIBC - E polarization case

    Ryoichi Sato, Hiroshi Shirai

    IEEE Antennas and Propagation Society International Symposium: Wireless Technologies and Information Networks, APS 1999 - Held in conjunction with USNC/URSI National Radio Science Meeting   4   2858 - 2861   1999

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    In this paper, based on the formulation of the Kobayashi and Nomura method, EM plane wave scattering by a material loaded trough on a ground plane is approximately analyzed by applying the simplest standard impedance boundary condition (SIBC). We adapted the SIBC to the eigen-function expansion. We have already presented the H polarization case in Sato and Shirai (1998). So the formulation is extended and derived here for the E polarization case. In order to check the validity of this approximation, numerical calculations have been done for various parameters. Differences between the E and H polarizations have been also discussed.

    DOI: 10.1109/APS.1999.789402

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  • SIBCを用いた媒質装荷方形溝による散乱電磁界の近似解析

    R. Sato, H. Shirai

    IEEJ Technical Report on EMT   EMT-98-101   105 - 110   1998.11

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  • 高層ビルの谷間における電磁波伝搬

    H. Shirai, S. Shinoda, M. Makino, A. Taguchi, K. Hashiguchi, R. Sawai

    第2回”統合型地理情報システムシンポジウム講演録(中央大学理工学研究所)   69 - 72   1998.10

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  • High frequency analysis of plane wave scattering by finite parallel plane waveguide cavities Reviewed

    H.Shirai, K.Watanabe, N.Hasegawa, H.Sekiguchi

    Proc. of 1998 Korea-Japan Joint Conference on Antennas Propagation, Electromagnetic Compatibilities, and Electromagnetic theory   137 - 140   1998.9

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  • Electromagnetic wave propagation down the urban canyons of high rise buildings Reviewed

    H.Shirai, K.Hashiguchi, R.Sawai, M.Makino, A.Taguchi, S.Shinoda

    Proc. of The 3rd International Symposium on Multi-Dimensional Mobile Communications.   348 - 351   1998.9

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  • 高周波曝露時における人体頭部局所SARに対する耳翼の影響に関する実験的検討

    H. Wakayanagi, T. Hamada, S. Watanabe, M. Taki, H. Shirai, Y. Yamanaka

    IEICE Technical Report on EMT   EMCJ98-41 ( 285 )   7 - 14   1998.9

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    The SARs in the human head models with the various shapes of auricles exposed to near-field of cellular telephones are experimentally evaluated with a electric-field probe in the human head model filled With brain-equivalent liquid phantom. It is shown that the existence of the ear affects the SAR distribution of the head model. Furthermore, the SAR distribution near the ear is dependent on the shape of the auricle. It is also shown that the SAR distribution evaluated experimentally agree with that obtained by numerical calculations.

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  • Comparison Between Measurement and Theoretical Evaluation for Micro Wave Local Dosimetry for Small Animals

    S. Watanabe, H. Wakayanagi, H. Shirai, Y. Okano, K. Ito, M. Taki

    Proc. of 1998 IEICE General Conference   1   1998.3

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  • Scattering Analysis from Loaded Trough on the Gound -E Polarization Case-

    R. Sato, H. Shirai

    Proc. of 1998 IEICE General Conference   1   1998.3

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  • Transient impulsive response from an interface between two media-Spectral theory of transients analysis-

    H. Shirai, H. Sato, E. Heyman

    Bulletin of The Institute of Sceience and Engineering   3   1998.3

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  • EM scattering analysis by a loaded trough on a ground using the SIBC

    R Sato, H Shirai

    IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM - ANTENNAS: GATEWAYS TO THE GLOBAL NETWORK, VOLS 1-4   2152 - 2155   1998

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  • Plane Wave Scattering from a Finite Parallel Plane Waveguide

    K. Watanabe, H. Shirai, N. Hasegawa, H. sekiguchi

    IEEJ Technical Report   EMT-97-34 ( 26 )   51 - 56   1997.11

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  • Plane Wave Scattering by a Polygonal Cylinder

    T. Hayashi, H. Shirai, H. Sekiguchi

    IEE Technical Report   EMT-97-36   61 - 66   1997.11

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  • High frequency analysis for evanescent modal excitation of flanged parallel plane waveguides

    H. Shirai

    Proc. of Sino-Japanese Joint Meeting on Optical Fibre Science and Electromagnetic Theory   167 - 172   1997.10

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  • Plane Wave Scattering from a Trough on the Ground -E Polarization Case-

    R. Sato, H. Shirai

    Bulletin of Education Faculty of Niigata University   39 ( 1 )   1 - 9   1997.10

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  • Electromagnetic Wave Scattering from a Loaded Trough -Approximation by Impedance Boundary Condition-

    R. Sato, H. Shirai

    Proc. of IEICE Society Conference   1   17   1997.9

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  • 非接触型液質計の検出特性

    Tozuka, Toda, H. Shirai, Ehara, Harada

    Proc. of 1997 Joint Conference on Chemical Engineers   92   1997.9

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  • On the Evaluation of the Liquid by Non-contact Sensor

    S. Tozuka, Toda, H. Shirai, Ehara, Harada

    IEICE Technical Report   SDM-97-87   39 - 46   1997.8

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  • Electromagnetic wave scattering by cracks -E polarization case- Reviewed

    R. Sato, H. Shirai

    Proc. of 1997 North American Radio Science URSI Meeting   303   1997.7

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  • Transient impulsive response from an interface between two media Reviewed

    H. Shirai

    Day on Diffraction '97 Abstracts   40   1997.6

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  • 電波暗室内におけるレーダ散乱断面積の測定に関する一検討 Reviewed

    白井宏, 石川高暁, 渡邊雄二

    電気学会論文誌   117-A ( 5 )   531 - 536   1997.5

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  • Plane Wave Scattering from a Gap onthe Ground Reviewed

    R. Sato, H. Shirai

    IEICE Trans on Electronics   J80-C-1 ( 5 )   179 - 185   1997.5

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  • Plane wave scattering by cracks Reviewed

    R.Sato, H.Shirai

    Proc. of 1997 Progress in Electromagnetics Research Symposium   2   660   1997.1

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  • GTD analysis for evanescent modal excitation Reviewed

    H Shirai, Y Matsuda, R Sato

    IEICE TRANSACTIONS ON ELECTRONICS   E80C ( 1 )   190 - 192   1997.1

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    A simple extension to treat evanescent modal excitation at the aperture of a parallel plane waveguide is shown here by GTD diffracted rays with complex propagation angles. Numerical comparison with other solution confirmed that our simple solution can be used for modal excitation estimation below the cut-off frequency.

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  • Electromagnetic plane wave scattering by a gap on a ground plane Reviewed

    Ryoichi Sato, Hiroshi Shirai

    Electronics and Communications in Japan, Part II: Electronics (English translation of Denshi Tsushin Gakkai Ronbunshi)   80 ( 11 )   22 - 29   1997

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:John Wiley and Sons Inc.  

    In this paper, electromagnetic plane wave scattering by a gap on a ground plane is analyzed. First, a rectangular trough is used as a gap model to obtain the rigorous representation of the scattering field based on a method by Kobayashi and Nomura. Then the simple formulae for the case when the aperture width is electrically narrow are derived for both H and E polarization. Numerical calculation is performed to check the validity of the derived formulae for various gap widths and depths. It is shown that our numerical results are in good agreement with those obtained from rigorous representations when the width is less than 0.2 wavelength, regardless of the depth. Comparison with other approximate solutions for the narrow case is also discussed. © 1998 Scripta Technica.

    DOI: 10.1002/(SICI)1520-6432(199711)80:11<22::AID-ECJB3>3.0.CO;2-T

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  • Acoustic analysis of plane wave transmission through a duct of a thick wall Reviewed

    R.Sato, H.Shirai

    Proc. of 3rd Joint Meeting of Acoustical Soc. of America and Acoustical Soc. of Japan   100 ( 4 )   2597   1996.12

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  • 導波・共振構造を有する物体による電磁波の散乱に関する研究(2)

    K. Kobayashi, H. Shirai

    Annual Report of the Institute of Science and Engineering   ( 3 )   29 - 32   1996.12

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  • 導体平板間の間隙による電磁波回折について

    R. Sato, H. Shirai

    IEEJ Technocal Report on EMT   EMT-96-69 ( 55 )   129 - 138   1996.10

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  • On the Evaluation of the Branch-cut Integral for Dielectric Waveguide Analysis, Part 2

    H. Nishino, H. Shirai

    IEEJ Techinical Report   EMT96-97 ( 89 )   75 - 84   1996.10

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  • クラックによる平面電磁波の散乱

    R. Sato, H. Shirai

    Proc. of 1996 IEICE Society Conference   21   1996.9

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  • Plane wave diffraction by a thick slit --TM case-- Reviewed

    R.Sato, H.Shirai

    Proc. of 1996 International Symposium on Antennas and Propagation   1   21 - 24   1996.9

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  • Plane wave diffraction by a thick slit --TE case-- Reviewed

    R.Sato, H.Shirai

    Proc. of 1996 Korea-Japan Joint Conference on Electromagnetic Theory and Compatibility   107 - 110   1996.8

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  • Electromagnetic Wave Scattering from a Crack on the Conducting Screen

    R. Sato, H. Shirai

    IEEJ Technical Report   EMT-96-17   1 - 10   1996.5

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  • Scattering by a narrow rectangular gap Reviewed

    R Sato, H Shirai

    IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM - 1996 DIGEST, VOLS 1-3   2   776 - 779   1996

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  • 導体平板上の方形溝による平面波の散乱―低周波近似の適用―

    R. Sato, H. Shirai

    IEEJ Technical Report on EMT   EMT-95-91   11 - 20   1995.12

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  • 誘電体導波路解析に伴う分岐積分評価について

    H. Nishino, H. Shirai

    IEEJ Technical Report on EMT   EMT-95-103   29 - 38   1995.12

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  • RCS測定データの時間領域解析について

    Y. Watanabe, H. Shirai, T. Ishikawa

    IEEJ Technical Report on EMT   EMT-95-88   53 - 62   1995.12

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  • 導波・共振構造を有する物体による電磁波の散乱に関する研究 Reviewed

    H. Shirai, K. Kobayashi

    Annual Report on the Institute of Science and Engineering, Chuo University   ( 2 )   25 - 27   1995.11

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  • 二媒質直線境界面におけるインパルス状線波源の散乱過渡応答 -Spectral theory of transients 法による解析 Reviewed

    佐藤弘康, 白井宏, E.ヘイマン

    電子情報通信学会論文誌   J78-C-I ( 10 )   439 - 447   1995.10

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  • STT analysis of transient response from a dielectric interface Reviewed

    H.Shirai, H.Sato

    Proc. of 4-th Sino-Japan Joint Meeting on Optical Fiber Science & Electromagnetic Theory (OFSET 95)   A   116 - 121   1995.9

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  • 有限長平行平板導波管による平面波の散乱解析

    N. Hasegawa, Y. Watanabe, H. Shirai

    Proc. of IEICE 1995 Elecrtronics Conference   4   1995.9

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  • 線波源による二媒質誘電体境界面からのインパルス過渡応答―透過波―

    H. Sato, H. Shirai

    Proc. of IEICE 1995 Society Conference   1995 ( 1 )   11 - 11   1995.9

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  • 狭い方形溝による平面波の散乱―E偏波の場合―

    R. Sato, H. Shirai

    Proc. of IEICE 1995 Society Conference   25   1995.9

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  • Plane wave scattering by a narrow trough on a ground plane Reviewed

    R.Sato, H.Shirai

    Proc. of 1995 Progress in Electromagnetics Research Symposium   558   1995.7

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  • 誘電体直線境界面からの散乱過渡応答 Reviewed

    白井宏

    電子情報通信学会論文誌   J78-C-I ( 3 )   125 - 133   1995.3

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  • 狭い方形溝による平面波の散乱

    R. Sato, H. Shirai

    Proc. of IEICE 1995 General Conference   40   1995.3

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  • 規範形状に対するRCS解析理論とその検証実験

    Y. Watanabe, T. Ishikawa, N. Hasegawa, H. Shirai

    1995年総合大会講演論文集(エレクトロニクス分冊-1),電子情報通信学会   1 ( 6 )   420 - 421   1995.3

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  • ELECTROMAGNETIC PLANE-WAVE SCATTERING BY A LOADED TROUGH ON A GROUND PLANE Reviewed

    R SATO, H SHIRAI

    IEICE TRANSACTIONS ON ELECTRONICS   E77C ( 12 )   1983 - 1989   1994.12

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    Electromagnetic plane wave scattering by a loaded trough on a ground plane has been analyzed by Kobayashi and Nomura's method. The field in each region is expressed first in terms of appropriate eigen functions, whose ex citation coefficients are determined by the continuity condition across the aperture of the trough. Simple far field expression which is suitable for numerical calculation for small aperture cases has been derived. Scattering far field patterns and radar cross section are calculated and compared with those obtained by other methods. Good agreements have been observed for all incident angles.

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  • Ray-mode coupling analysis of EM wave scattering by a partially filled trough Reviewed

    H.Shirai

    Journal of EM Waves and Applications   8 ( 11 )   1443 - 1464   1994.11

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  • 部分的に媒質を装荷した方形溝による平面電磁波の散乱―E偏波の場合―

    R. Sato, H. Shirai

    IEEJ Technical Report on EMT   EMT-94-35   1 - 10   1994.10

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  • STT法による二媒質直線境界面におけるインパルス過渡応答解析

    H. Sato, H. Shirai, E. Heyman

    IEEJ Technical Report on EMT   EMT-94-87   55 - 64   1994.10

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  • RCS測定実験に関する一考察

    T. Ishikawa, Y. Watanabe, T. Kamo, H. Shirai

    IEEJ Technical Report on EMT   EMT-94-94   121 - 130   1994.10

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  • Electromagnetic plane wave scattering by a loaded trough on the ground Reviewed

    R.Sato, H.Shirai

    Proc. International Conference on Mathematical Method in Electromagnetic Theoty   358 - 361   1994.9

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  • 二媒質誘電体境界面におけるインパルス状線波源による散乱解析

    佐藤弘康, 白井宏

    1994年秋季全国大会講演論文集(エレクトロニクス分冊-1),電子情報通信学会   12   1994.9

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  • 導体平板上に設けられた方形溝による平面電磁波の散乱―E偏波の場合―

    R. Sato, H. Shirai

    IEEJ Technical Report on EMT   EMT-94-32   57 - 66   1994.7

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  • 部分的に媒質を装荷した導体平板上の方形溝による平面電磁波の散乱

    R. Sato, H. Shirai

    1994年春季全国大会講演論文集,電子情報通信学会   2   531   1994.3

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  • Lecture Feedback form Students

    Hiroshi Shirai

    Kusanomidori   74   64   1994.3

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  • 中央大学における高周波電磁界測定解析装置の概要

    T. Ishikawa, H. Shirai

    1994年春季全国大会講演論文集,電子情報通信学会   2   134   1994.3

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  • 二次元自由空間中のインパルス状線波源に対するグリーン関数

    H. Sato, H. Shirai

    Proc. of 1994 IEICE Spring Confernce   2   506   1994.3

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  • RAY MODE-COUPLING ANALYSIS OF PLANE-WAVE SCATTERING BY A TROUGH (VOL E76B, PG 1563, 1993)

    H SHIRAI, K HIRAYAMA

    IEICE TRANSACTIONS ON COMMUNICATIONS   E77B ( 2 )   280 - 280   1994.2

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  • RAY MODE-COUPLING ANALYSIS OF EM WAVE SCATTERING BY A PARTIALLY FILLED THROUGH Reviewed

    H SHIRAI

    IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM 1994, VOLS I-III   1062 - 1065   1994

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  • RAY MODE-COUPLING ANALYSIS OF PLANE-WAVE SCATTERING BY A TROUGH Reviewed

    H SHIRAI, K HIRAYAMA

    IEICE TRANSACTIONS ON COMMUNICATIONS   E76B ( 12 )   1558 - 1563   1993.12

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    Electromagnetic plane wave scattering by a wide trough on the ground has been analyzed by high frequency asymptotic techniques based on Geometrical Theory of Diffraction. Field in the trough region has been formulated in terms of parallel plane waveguide modes, whose excitation (coupling) coefficients are obtained by ray-mode conversion techniques. Numerical calculation has been done extensively and thus obtained results are then compared with those by other methods. Good agreements have been observed except for oblique incidence case. It is found that first and secondary modal re-radiation fields from the indented trough region play an important role for scattering far field, and primary edge diffracted field contributes mainly to reflection boundary direction.

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  • 誘電体スラブ導波路に対するGreen関数について

    T. Fuse, H. Shirai

    IEEJ Technical Report on EMT   EMT-93-94   141 - 150   1993.11

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  • 導体平板上の損失誘電体を装荷した方形溝による平面電磁波の散乱

    佐藤亮一, 白井宏

    IEEJ Technical Report on EMT   EMT-93-63   93 - 102   1993.11

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  • エバネッセント波に対する幾何光学的回折理論の拡張

    H. Matsuda, H. Shirai

    IEEJ Technical Report on EMT   EMT-93-70   131 - 140   1993.11

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  • Multiple interaction effects for RCS Calculation by a trough on the ground Reviewed

    H.Shirai

    Proc. of 1993 International Symposium on Antennas and Electromagnetic Theory (ISAE'93)   84 - 87   1993.9

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  • Ray-mode conversion analysis at the aperture of the open-cavities Reviewed

    H.Shirai

    Proc. of 1993 Day on Diffraction   37   1993.6

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  • 導体平板上の方形溝による平面電磁波の散乱 Reviewed

    佐藤亮一, 白井宏, 平山和宏

    電子情報通信学会論文誌   J-76-C-I ( 4 )   107 - 109   1993.4

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  • 導体平板上の矩形溝による平面電磁波の散乱

    R. Sato, H. Shirai

    1993年春季全国大会講演論文集,電子情報通信学会   2   465   1993.3

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  • GTDによるストリップ回折界の精度評価 Reviewed

    白井宏, 宮賢一

    電気学会論文誌   113-A ( 3 )   147 - 156   1993.3

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  • ELECTROMAGNETIC-WAVE SCATTERING BY A TROUGH ON THE GROUND Reviewed

    H SHIRAI, R SATOH

    IEEE ANTENNAS AND PROPAGATION SOCIETY, INTERNATIONAL SYMPOSIUM 1993, VOLS 1-3   86 - 89   1993

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  • 二媒質直線境界よりの散乱過渡応答

    K. Yamane, H. Shirai

    IEEJ Technical Meeting on EMT   EMT-92-102   51 - 60   1992.10

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  • 光線とモードの等価変換について Invited

    H. Shirai

    1992年秋季全国大会講演論文集,電子情報通信学会   2   515 - 516   1992.9

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  • Ray mode coupling analysis of plane wave scattering by a trough Reviewed

    H.Shirai, K.Hirayama

    Proc. of 1992 International Symposium on Antennas and Propagation   2   613 - 616   1992.9

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  • Electromagnetic plane wave scattering by a trough on the ground Reviewed

    H.Shirai, K.Hirayama

    Proc. of 1992 URSI Radio Science Meeting   35   1992.7

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  • ANALYSIS OF TIME TRANSIENT EM FIELD RESPONSE FROM A DIELECTRIC SPHERICAL CAVITY Reviewed

    H SHIRAI, E NAKANO, M YANO

    IEICE TRANSACTIONS ON ELECTRONICS   E75C ( 5 )   627 - 634   1992.5

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    Transient responses by a dielectric sphere have been analyzed here for a dipole source located at the center. The formulation has been constructed first in the frequency domain, then transformed into the time domain to obtain for an impulsive response by two analytical methods, namely the Singularity Expansion Method and the Wavefront Expansion Method. While the former method collects the contributions around the singularities in the complex frequency domain, the latter gives us a result which is a summation of each successive wavefront arrivals. A Gaussian pulse has been introduced to simulate an impulse response result. The Gaussian pulse response is analytically formulated by convolving Gaussian pulse with the corresponding impulse response. Numerical inversion results are also calculated by Fast Fourier Transform Algorithm. Numerical examples are shown here to compare the results obtained by these three methods and good agreement are obtained between them. Comments are often made in connection with the corresponding two dimensional cylindrical case.

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  • 導体平板上の矩形溝によるレーダ散乱断面積

    平山和宏, 白井宏

    電子情報通信学会1992年春季全国大会講演論文集   2   447   1992.3

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  • GTDによるストリップ回折界の精度評価

    H. Shirai, K. Miya

    IEEJ Technical Report on EMT   EMT-91-146   69 - 78   1991.12

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  • Analysis of time domain scattering from a dielectric spherical cavity

    H. Shirai, Nakano, M.Yano

    IEEJ Technical Report on EMT   EMT-91-129   31 - 39   1991.10

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  • Transient responses by dielectric cylinders and spheres excited by sources at their centers Reviewed

    H.Shirai

    Proc. International Conference on Mathematical Method in Electromagnetic Theoty   365 - 368   1991.9

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  • Time transient analysis of wave scattering by simple shapes Invited Reviewed

    H.Shirai

    Proc. International Seminar Workshop on Analytical and Numerical Methods in Electromagnetic Wave Theory   209 - 218   1991.6

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  • Transient responses by dielectric cylinders and spheres excited by sources at their centers Reviewed

    H.Shirai

    Proc. of 1991 North American Radio Science Meeting   126   1991.6

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  • 微小放電から放射される電磁波

    堀口,伊藤, 白井,遠藤

    平成3年電気学会全国大会,電気学会   2   127   1991.4

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  • 二媒質直線境界よりの散乱過渡応答

    白井宏

    電子情報通信学会1991年春季全国大会   2   483   1991.3

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  • Era of Satelite Communication

    Hiroshi Shirai

    Kusanomidori   41   31 - 32   1991.1

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  • TRANSIENT-RESPONSE BY A DIELECTRIC CYLINDER DUE TO A LINE SOURCE AT THE CENTER Reviewed

    H SHIRAI, A HAMAKOSHI

    IEICE TRANSACTIONS ON COMMUNICATIONS ELECTRONICS INFORMATION AND SYSTEMS   74 ( 1 )   157 - 166   1991.1

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    Time transient scattering field due to a line source located at the center of the dielectric cylinder has been calculated. In the analysis, the corresponding time harmonic result has been formulated first rigorously, then the high frequency asymptotic expansion result has been derived. Thus obtained result is found to coincide with the one constructed directly by ray approximation. Fourier inversion for an impulsive response has been done by two methods, namely the Singularity Expansion Method and wavefront expansion method. While the former method collects the contributions around the singularities in the complex frequency domain, the latter gives us a result which is a summation of each successive wavefront arrivals. A finite Hilbert transform technique has been introduced to recover the causal responses of odd-time caustic passing wavefronts. Also derived are results of numerical inversion by Fast Fourier Transform Technique for the frequency band limited incident pulses. A Gaussian pulse has been introduced to simulate an impulse response result, and a raised cosine pulse which de-emphasizes the low frequency defects of asymptotically constructed frequency spectrum confirms the usefulness of ray solution.

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  • Planewave scattering from trough on the ground

    Kazuhiro Hirayama, Hiroshi Shirai

    Proc. of IEICE 1990 Fall Conference   2   17   1990.10

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  • Ray Tracing法による誘電体スラブ線路の曲がり部の解析

    D. Takashima, H. Shirai

    Proc. of 1990 IEICE Fall Conference   2   353   1990.10

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  • Transient response by a dielectric cylinder due to a line source at the center. Reviewed

    H.Shirai, A.Hamakoshi

    Proc. of 1990 Japan-China Joint Meeting on Optical Fiber Science & Electromagnetic Theory   EMT-90-128   1 - 8   1990.10

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  • Conference Report on 1990 IEEE APS/URSI

    K. Kagoshima, K. Kobayashi, H. Shirai

    IEICE Technical Report   A.P90-44   31 - 38   1990.8

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  • Electromagnetic plane wave diffraction by a wide and thick slit Reviewed

    H.Shirai

    Proc. of 1990 USNC/URSI Radio Science Meeting   360   1990.5

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  • Transient pulse response from a line source in a dielectric cylinder

    A. Hamakoshi, Hiroshi Shirai

    Proc. of IEICE 1990 Spring Conference   2   445   1990.3

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  • Scalar planewave scattering by a finite pipe

    Hiroyuki Fukuda, Hiroshi Shirai

    Technical Report of IEEJ Technical Meeting on EMT   EMT-90-19   11 - 20   1990.3

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  • 中空パイプの開口端におけるスカラー平面波の散乱

    H. Fukuda, H. Shirai

    IEICE 1990 General Conference   2   436   1990.3

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  • 剛体円筒の開口端における導波モードの反射 Reviewed

    白井宏

    日本音響学会誌   46 ( 2 )   95 - 103   1990.2

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  • 有限長で終端された平行平板導波管による平面波の散乱

    Junji Sugawara, Hiroshi Shirai

    IEEJ Technical Meeting on EMT   EMT-89-85   129 - 138   1989.10

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  • Electromagnetic plane wave scattering by a wide open-ended parallel plate waveguide with a finite termination Reviewed

    H.Shirai

    Proc. of 1989 URSI International Symposium on Electromagnetic Theory   249 - 251   1989.8

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  • Time Transient Response and Complex Resonance Frequencies Invited

    Hiroshi Shirai

    Technical Report of IEICE Technical Meeting on AP   AP-88-90   49 - 54   1988.11

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  • Modal Reflection at Circular Waveguide Aperture Reviewed

    Hiroshi Shirai

    Technical Report of IEEJ Technical Meeting on EMT   EMT-88-90   17 - 26   1988.10

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  • Ray-mode analysis of plane wave coupling into a large open circular waveguide Reviewed

    H.Shirai

    Proc. of 1988 IEEE Antennas & Propagation Society (AP-S) International Symposium   I   428   1988.6

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  • 海外旅行へのアドバイス―米国を例にして―

    白井宏

    中央評論   39 ( 4 )   87 - 93   1987.12

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  • GO beam diffusion in a parallel plane waveguide

    Hiroshi Shirai

    Proc. of IEICE 1987 Conference   1   220   1987.11

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  • RAYS AND MODES FOR PLANE-WAVE COUPLING INTO A LARGE OPEN-ENDED CIRCULAR WAVE-GUIDE Reviewed

    H SHIRAI, LB FELSEN

    WAVE MOTION   9 ( 6 )   461 - 482   1987.11

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  • Planewave Scattering by a Waveguide Aperture

    Hiroshi Shirai

    Technical Report of IEEJ Technical Meeting on EMT   EMT-87-87   117 - 126   1987.10

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  • RAYS, MODES AND BEAMS FOR PLANE-WAVE COUPLING INTO A WIDE OPEN-ENDED PARALLEL-PLANE WAVE-GUIDE Reviewed

    H SHIRAI, LB FELSEN

    WAVE MOTION   9 ( 4 )   301 - 317   1987.7

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  • Hybrid ray-mode analysis of coupling into large open waveguides Reviewed

    H.Shirai, L.B.Felsen

    Proc. of 1987 USNC/URSI Radio Science Meeting   222   1987.6

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  • Planewave Scattering from Aperture of a Parallel Plane Waveguide

    Hiroshi Shirai, L.B. Felsen

    Proc. of IEICE 1987 General Conference   3   135   1987.3

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  • HYBRID RAY-MODE ANALYSIS OF HIGH-FREQUENCY WAVE COUPLING INTO LARGE WAVE-GUIDES AND CAVITIES Reviewed

    LB FELSEN, H SHIRAI

    OPTICS LETTERS   12 ( 1 )   7 - 9   1987.1

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  • Ray acoustic analysis of plane wave coupling into large open waveguides: Plane parallel geometry Reviewed

    L.B.Felsen, H.Shirai

    Proc. of 112th Acoustical Society of America (ASA) Meeting   80 ( S1 )   S105   1986.12

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  • Ray acoustic analysis of plane wave coupling into large open waveguides: Circular geometry Reviewed

    H.Shirai, L.B.Felsen

    Proc. of 112th ASA Meeting   80 ( S1 )   S105   1986.12

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  • SPECTRAL METHOD FOR MULTIPLE EDGE-DIFFRACTION BY A FLAT STRIP Reviewed

    H SHIRAI, LB FELSEN

    WAVE MOTION   8 ( 6 )   499 - 524   1986.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ELSEVIER SCIENCE BV  

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  • DEEMPHASIZING LOW-FREQUENCY DEFECTS IN GTD ANALYSIS OF PULSED SIGNAL SCATTERING BY A PERFECTLY CONDUCTING FLAT STRIP Reviewed

    H SHIRAI

    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION   34 ( 10 )   1261 - 1266   1986.10

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

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  • WAVE-FRONT AND RESONANCE ANALYSIS OF SCATTERING BY A PERFECTLY CONDUCTING FLAT STRIP Reviewed

    H SHIRAI, LB FELSEN

    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION   34 ( 10 )   1196 - 1207   1986.10

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  • HIGH-FREQUENCY MULTIPLE DIFFRACTION BY A FLAT STRIP - HIGHER-ORDER ASYMPTOTICS Reviewed

    H SHIRAI, LB FELSEN

    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION   34 ( 9 )   1106 - 1112   1986.9

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  • Puise wave scattering by a conducting strip -GTD Analysis-

    Hiroshi Shirai, L.B. Felsen

    Proc. of IECE 1986 Optical and EM Wave Conference   1   126 - 126   1986.9

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  • MODIFIED GTD FOR GENERATING COMPLEX RESONANCES FOR FLAT STRIPS AND DISKS Reviewed

    H SHIRAI, LB FELSEN

    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION   34 ( 6 )   779 - 790   1986.6

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    Web of Science

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  • Spectral method for multiple edge diffraction by a flat strip. Reviewed

    H.Shirai, L.B.Felsen

    Proc. of 1986 USNC/URSI Radio Science Meeting   70   1986.6

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  • Modified GTD for generating complex resonances for flat strips and disks Reviewed

    H.Shirai, L.B.Felsen

    Proc. of 1985 North American Radio Science Meeting   224   1985.6

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  • Wavefronts and resonances in transient scattering by a flat strip Reviewed

    H.Shirai, E.Heyman, L.B.Felsen

    Proc. of 1984 USNC/URSI Radio Science Meeting   34   1984.6

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  • Diffraction of cylindrical wave by smooth and polygonal cylinders. Reviewed

    H.Shirai, K.Hongo, H.Kobayashi

    Trans. of IECE of Japan   E66 ( 3 )   116 - 123   1983.2

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  • Equi-contour Lines Around Conducting Wedge

    Hiroshi Shirai, Kohei Hongo

    Proc. of 1981 IECE general conference   3   11   1981.4

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  • NUMERICAL STUDY OF THE NEAR-FIELD RADIATED BY AN INFINITELY LONG SLOT ON CIRCULAR CONDUCTING CYLINDER Reviewed

    H SHIRAI, K HONGO

    JOURNAL OF APPLIED PHYSICS   51 ( 9 )   5047 - 5050   1980

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Books

  • Advances in Mathematical Methods for Electromagnetics

    Hiroshi Shirai( Role: Contributor"High Frequency Hybrid Ray-Mode Techniques”, Chapter 7)

    The Institute of Engineeering and Technology (IET)  2020.12 

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    Total pages:p. 748   Responsible for pages:pp. 166-188   Language:English   Book type:Scholarly book

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  • Technical Writing Guide Book

    Hiroshi Shirai( Role: Sole author)

    Corona Publishing Co.,Ltd.  2019.1  ( ISBN:9784339078206

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    Total pages:125p.   Language:Japanese   Book type:Scholarly book

    誰が読んでも間違いなく同じ結論に達するためには,どのように技術文書をまとめればよいか。理工系の学生が悩む技術文書や技術論文,実験レポートの論理的な書きかたに,発表のしかたを含めて丁寧にまとめた。

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  • ``Electromagnetic Analysis (Sec. 5.2)'' in 100-year History of the Institute of Electronics, Information and Communication Engineers

    IEICE( Role: Sole author``Electromagnetic Analysis (Sec. 5.2)'' in 100-year History of the Institute of Electronics, Information and Communication Engineers, pp.311-312, IEICE)

    IEICE  2017.9 

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    Total pages:447   Responsible for pages:311-312   Language:Japanese  

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  • Elecromagnetic Inverse Analyses

    IEE Committee of, Electromagnetic Inverse Analyses Ed( Role: ContributorChap.7 Method using RCS angular variation)

    IEE Japan  2015.5 

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    Total pages:67 p.   Responsible for pages:pp. 38-44   Language:Japanese   Book type:Scholarly book

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  • Geometrical Theory of Diffraction

    Hiroshi Shirai( Role: Sole author)

    Corona Publishig Co.  2015.4 

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    Total pages:208 p.   Responsible for pages:208   Language:Japanese   Book type:Scholarly book

    電磁波解析手法の一つである幾何光学的回折理論の考え方,使い方について応用例を含めて解説している。本理論は無線通信などの高周波漸近解析手法の一つで,電磁波に関する物理的な諸法則・原理と巧みな数学的取扱いにより導かれる。

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  • Electromagnetics

    Toru Uno, Hiroshi Shirai( Role: Joint author)

    Corona Publishing Co.,ltd.  2010.6 

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    Total pages:415 p.   Responsible for pages:415   Language:Japanese   Book type:Scholarly book

    電磁気学の本質をきちんとつかみたい人のための本。偉大な先人達が導いた式の導出やその意味を懇切丁寧に解説した。電磁気学にはベクトル解析の知識が不可欠であり,本書で使う記号に慣れてもらう意味で,数学的準備の章も用意した。

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  • Antenna Engineering Handbook (2nd ed.)

    IEICE ed( Role: Contributor12.2.4 GTD, 12.2.10 Other High Frequency Approximations)

    Ohmsha  2008.7  ( ISBN:9784274205446

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    Total pages:1074 p.   Responsible for pages:pp. 785-788, pp.797-798   Language:Japanese   Book type:Scholarly book

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  • Day Diffranction '97

    Hiroshi Shirai, Hiroyasu Sato, V.S.Buldyrev, V.M.Babich, I.V.Andronov, V.E.Grikurov, A.P.Kiselev( Role: ContributorChap.12, Transient impulsive response from an interface between two media)

    Faculty of Physics, St.Ptersburg University,Russia  1997.12 

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    Responsible for pages:pp. 91-100   Language:English   Book type:Scholarly book

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  • Day Diffranction '97(Eds.V.S.Buldyrev, V.M.Babich, I.V.Andronov, V.E.Grikurov, and A.P.Kiselev)

    H.Shirai, H.Sato( Role: Joint authorChap.12,Transient impulsive response from an interface between two media)

    Faculty of Physics, St.Ptersburg University,Russia  1997.12 

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    Responsible for pages:91-100   Language:English   Book type:Scholarly book

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  • Introduction to Applied Analysis (Complex Analysis, Fourier Analysis, Laplace Tranceformation)

    Hiroshi Shirai( Role: Sole author)

    Corona Publishing Co.,Ltd.  1993.6 

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    Total pages:265 p.   Language:Japanese   Book type:Scholarly book

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  • Analytical and numerical methods in electromagnetic wave theory

    M.Hashimoto, M.Idemen, O.A.Tretyakov, Authors( Role: ContributorWavefront and complex resonance descriptions in time transient EM responses by simple geometries (Chap.8))

    Science House Co. Ltd  1993.2 

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    Total pages:590p.   Responsible for pages:pp.373-417   Language:English   Book type:Scholarly book

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  • Solid Mechanics Research for Quantitative Non-Destructive Evaluation

    J.D.Achenbach, Y.Rajapakse, Authors( Role: ContributorHybrid ray-mode and wavefront-resonance techniques for acoustic emission and scattering in multiwave layered media)

    Martinus Nijhoff Publishers (The Netherlands)  1987.4 

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    Total pages:438 p.   Responsible for pages:pp. 377-388   Language:English   Book type:Scholarly book

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  • Hybrid ray-mode and wavefront-resonance techniques for acoustic emission and scattering in multiwave layered media ( pp. 377-388 ) in Solid Mechanics Research for Quantitative Non-Destructive Evaluation( 438p. )

    J.D.Achenbach, Y.Rajapakse, Authors( Role: Sole author)

    Martinus Nijhoff Publishers (The Netherlands)  1987.4 

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  • Micro Mouse -How to make microcomputer Robots-

    Hiroshi Shirai et. al, H. Kanayama( Role: ContributorSec 2.8, Sec.2.13)

    近代科学社  1981.9 

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    Total pages:186p.   Responsible for pages:pp.117-121, pp.149-155   Language:Japanese   Book type:General book, introductory book for general audience

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Presentations

  • High Frequency EM Scattering by a Large Building with Multiple Windows

    C. M. Bui, H. Shirai

    24th edition of the International Conference on Electromagnetics in Advanced Applications (ICEAA 2023)  2023.10 

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  • Extended Physical Optics Approximation for Edge Diffraction by Dielectric Wedges

    D. M. Nguyen, H. Shirai

    24th edition of the International Conference on Electromagnetics in Advanced Applications (ICEAA 2023)  2023.10 

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  • High Frequency Scattering by a Thick Conducting Plate With Multiple Holes -E Polarization Case-

    C. M. Bui, H. Shirai

    URSI General Assembly and Scientific Symposium 2023 (URSI GASS 2023)  2023.8 

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  • TM Polarized Plane Wave Scattering by a Conducting Plate with Multiple Holes

    C. M. Bui, H. Shirai

    2023 International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting  2023.7 

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  • Uniform Asymptotic Solution for Edge Diffraction of H-Polarized Electromagnetic Plane Wave by Dilectric Wedges

    D. M. Nguyen, H. Shirai

    URSI International Symposium on Electromagnetic Theory 2023 (URSI EMTS 2023)  2023.5 

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  • D. M. New Formulation of Physical Optics Approximation for Edge Diffraction by Dielectric Wedges

    D. M. Nguyen, H. Shirai, S.-Y. Kim

    2022 International Conference on Electromagnetics in Advanced Applications (ICEAA 2022)  2022.9 

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  • Fundamental Analysis on EM Wave Scattering by Simple Cracks on Conducting Plane

    R. Sato, H.Shirai

    2022 Japan Radio Science Meeting (URSI-JRSM)  2022.9 

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  • TM Polarized Plane Wave Scattering by a Window on a Thick Conducting Wall International conference

    C. M. Bui, H. Shirai

    2022 IEEE International Symposium on Antennas and Propagation (APS/URSI 2022)  ( Denver, USA. )   2022.7  IEEE

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  • Extended Physical Optics Approximation for Electromagnetic Wave Scattering from Penetrable Objects Invited International conference

    Hiroshi Shirai

    XXXIV General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS 2021)  2021.8  URSI

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  • Uniform Asymptotic Solution for Dielectric Wedge Diffraction Based on Equivalent Currents Invited International conference

    D. M. Nguyen, H. Shirai, S.-Y. Kim

    XXXIV General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS 2021)  2021.8  URSI

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  • GO-Based Equivalent Current Formulation for Scattering from Circular Conducting Cylinders and Strips International conference

    N. Q. Ta, H. Shirai

    2021 International Conference on Electromagnetics and Advanced Applications (ICEAA 2021)  2021.8  ICEAA

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  • Approximate analysis of EM wave scattering from two cracks on a ground plane International conference

    R. Sato, H. Shirai

    2020 ISAP International Symposium on Antennas and Propagation  ( Osaka, Japan )   2021.1  IEICE

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  • High Frequency Asymptotic Evaluation for Electromagnetic Scattering from a Circular Conducting Cylinder -E Polarization- International conference

    N. Q. Ta, H. Shirai

    2020 International Conference on Communications and Electronics (ICCE)  ( Phu Quoc, Vietnam )   2021.1  IEEE

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  • TE Plane Wave Diffraction by Window Aperture on a Thick Conducting Wall International conference

    K. N. Nguyen, H. Shirai

    2020 IEEE International Conference on Advanced Tecnologies for Communications (ATC 2020)  ( Nha Trang, Vietnam )   2020.10  IEEE

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  • High Frequency Diffraction by Thick Loaded Conducting Slits -H Polarization Case- International conference

    K. N. Nguyen, H. Shirai

    2020 IEEE International Symposium on Antennas and Propagation (APS/URSI 2020)  ( Montreal, Canada (Online Conf.) )   2020.7  IEEE

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  • Fundamental study on electromagnetic wave scattering from two cracks on conducting plane

    Ryoichi Sato, Hiroshi Shirai

    IEICE Technical Meeting on Electromagnetic Theory (EMT)  ( Saga )   2019.11  IEICE

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  • High Frequency Asymptotic Evaluation of PO Integral for EM Scattering from PEC Circular Cylinder International conference

    T. Q. Ngoc, H. Shirai

    2019 International Conference on Electromagnetics and Advanced Applications (ICEAA 2019)  ( Granada, Spain )   2019.9  ICEAA

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  • Fundamental Analysis of Electromagnetic Wave Scattering from Multi-layered Window Glass in Multi-frequency Band International conference

    R. Sato, H. Shirai

    2019 International Conference on Electromagnetics and Advanced Applications (ICEAA 2019)  ( Granada, Spain )   2019.9  ICEAA

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  • High Frequency Diffraction by Thick Loaded Conducting Slits -H Polarization Case- International conference

    K. N. Nguyen, H. Shirai

    2019 IEEE International Symposium on Antennas and Propagation (APS/URSI 2019)  ( Atlanta, GA USA )   2019.7  IEEE

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  • High Frequency Diffraction by Rectangular Hole in a Thick Conducting Screen -H Polarization Case- International conference

    K. N. Nguyen, H. Shirai

    2019 PhotonIcs & Electromagnetics Research Symposium (PIERS 2019)  ( Rome, Italy )   2019.6  PIERS

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  • Plane Wave Diffraction by Loaded Slit in a Thick Conducting Screen

    K. N. Nguyen, H. Shirai

    IEICE Technical Meeting on Electromagnetic Theory (EMT)  ( tottri )   2018.11  IEICE

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  • High Frequency Scattering from Dielectric Rectangular Cylinders -TE Polarization-

    H. N. Quang, H. Shirai

    IEICE Technical Meeting on Electromagnetic Theory (EMT)  ( Tottori )   2018.11  IEICE

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  • Electromagnetic Plane Wave Diffraction by Thick Conducting Slits -E Polarization Case- International conference

    K. N. Nguyen, H. Shirai

    2018 International Symposium on Antennas and Propagation (ISAP 2018)  ( Busan, Korea )   2018.10  IEICE

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  • EM Wave Scattering by a Window on a Wall International conference

    H. Shirai, M. Shimizu, R. Sato

    2018 International Conference on Electromagnetics and Advanced Applications  ( Cartagena de Indias, Columbia )   2018.9  ICEAA

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  • Reflection and Transmission Features of Scattered Field from Multi-layered Window Glass in High Frequency Band International conference

    R. Sato, H. Shirai

    Progress in Electromagnetics Research Symposium (PIERS 2018)  2018.8  PIERS

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  • Diffraction Study with Prof. Kohei Hongo International conference

    H. Shirai

    Progress in Electromagnetics Research Symposium (PIERS 2018)  2018.8  PIERS

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  • High Frequency Scattering from Conducting Rectangular Cylinder via Surface Equivalence Theorem International conference

    H. N. Quang, H. Shirai

    Progress in Electromagnetics Research Symposium (PIERS 2018)  2018.8  PIERS

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  • H-polarized Plane Wave Diffraction by Thick Conducting Slits International conference

    K. N. Nguyen, H. Shirai

    Progress in Electromagnetics Research Symposium (PIERS 2018)  2018.8  PIERS

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  • Plane Wave Scattering from Two Cracks on Conducting Plane International conference

    R. Sato, H. Shirai

    Progress in Electromagnetics Research Symposium (PIERS 2018)  ( Toyama, Japan )   2018.8  PIERS

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  • H-polarized Plane Wave Diffraction by Thick Conducting Slits International conference

    K. N. Nguyen, H. Shirai

    2018 IEEE International Conference on Communications and Electronics (ICCE 2018  2018.7  IEEE

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  • High Frequency Wedge Diffraction Analysis via Surface Equivalence Theorem International conference

    H. N. Quang, H. Shirai

    2018 IEEE International Symposium on Antennas and Propagation (APS/URSI 2018)  ( Boston, USA )   2018.7  IEEE

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  • Proposal of Novel Reflection/Transmision Coefficient for Efficient Propagation Analysis at Outdoor-indoor Interface Environment

    R. Sato, A. Takatori, H. Shirai

    2nd URSI AT-RASC  ( Gran Canaria, Spain )   2018.5  URSI

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  • High-frequency Asymptotic Solution of Scattering Field by Three-layered Dielectric Slab for Accurate Propagation Analysis International conference

    R. Sato, H. Shirai

    2017 International Symposium on Antennas and Propagation  2017.11  IEICE

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  • A Study on Reflection/transmission Characteristics by Multi-layered Dielectric Slab for Efficient Radio Wave Propagation Analysis

    R. Sato, H. Shirai

    Technical Meeting on Electromagnetic Theory (EMT)  2017.11 

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  • Plane Wave Diffraction by a Rectangular Hole in a Thick Conducting Screen

    K. N. Nguyen, H. Shirai

    Technical Meeting on Electromagnetic Theory  2017.11 

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  • Electromagnetic Plane Wave Scattering by a Rectangular Hole in a Thick Conducting Screen

    K. N. Nguyen, H. Shirai

    2017 International Conference on Electromagnetics and Advanced Applications  2017.9 

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  • High Frequency Plane Wave Scattering Analysis from Dielectric Cuboids - TM Polarization - International conference

    H. N. Quang, H. Shirai

    2017 URSI General Assembly and Scientific Symposium (GASS)  2017.8  URSI

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  • Design of Multiband Antennas Using Asymmetric E-CRLH TL unit cells

    H. B. Chu, H. Shirai

    2017 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting  2017.7 

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  • Efficient Approximate Solution of Scattering Field by Three-layered Dielectric Slab for Accurate Propagation Analysis

    R. Sato, H. Shirai

    2017 International Conference on Computational Electromagnetics  2017.3 

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  • Dielectric Permittivity Estimation Based On Free Space Method

    A. N. Nguyen, H. Shirai

    2017 IEICE General Conference  2017.3 

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  • Effect of the Gap Width to the Input Impedance of Dipole Antennas by FDTD Method

    Z. Zheng, H. Shirai

    2017 IEICE General Conference  2017.3 

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  • E Polarized Plane Wave Diffraction by a Thick Loaded Slit

    M. Shimizu, H. Shirai, R. Sato

    IEICE Technical Group meeting on Electromagnetic Theory  2016.11 

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  • Reconstruction of Dielectric Polygonal Scatterers using Electromagnetic Wave Back Scattering Value

    A. Kisumi, H. Shirai

    IEICE Technical Group Meeting on Electromagnetic Theory  2016.11 

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  • A Study on Vehicular Modelings for FDTD Analysis

    T. Ishifuji, Z. Zheng, H. Shirai

    IEICE Technical group Meeting on Electromagnetic Theory  2016.11 

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  • A Compact D-CRLH Metamaterial Antenna for WLAN and WiMAX Multiband

    H. N. Quang, H. Shirai

    2016 International Symposium on Antennas and Propagation  2016.10 

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  • Radiation Efficiency of Multi-arm Open-ended Spherical Helix Antennas International conference

    K. Fujita, H. Shirai

    2016 International Symposium on Antennas and Propagation  2016.10  IEICE

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  • Electromagnetic Scattering by Simplified Crack Models on Conducting Ground Plane

    R. Sato, H. Shirai

    2016 International Symposium on Antennas and Propagation  2016.10 

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  • Novel Closed-Form Solutions for Designing Extended-Composite Right/Left-Handed Transmission Lines

    H. B. Chu, H. Shirai

    2016 International Conference on Electromagnetics in Advanced Applications  2016.9 

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  • Difference on the Radiation Efficiency between Two Spherical Helix Antennas

    K. Fujita, H. Shirai

    2016 IEICE Society Conference  2016.9 

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  • On Efficiency Improvement of Simplified Ray-launching Method for Indoor Propagation Problem

    R. Sato, H. Shirai

    2016 IEICE Society Conference  2016.9 

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  • Diffraction by Thick and Loaded Slit -E-polarization Case-

    H. Shirai, M. Shimizu, R. Sato

    2016 International Symposium on Electromagnetic Theory  2016.8 

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  • Far Field Radiation Pattern Analysis of an Antenna Installed in an Automobile

    Z. Zheng, H. Shirai

    2016 URSI Asia-Pacific Radio Science Conference  2016.8 

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  • Ray-mode Conversion Technique Applied to Thick Slit Diffraction

    H. Shirai, M. Shimizu, R. Sato

    16th International Conference on Mathematical Methods in Electromagnetic Theory  2016.7 

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  • Evanescent Modal Effect to E Polarized Plane Wave Diffraction by a Wide and Thick Slit

    H. Shirai, M. Shimizu, R. Sato

    2016 IEEE International Symposium on Antennas and Propagation  2016.6 

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  • Radiation Efficiency Considering Stored Energy Inside Small Thin Spherical Shell Shaped Antennas

    K. Fujita, H. Shirai

    2016 IEICE General Conference  2016.3 

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  • A study on electromagnetic wave scatteringform dielectric cylinders

    J. Aiso, H. Shirai

    2015 IEICE General Conference  2016.3 

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  • Wall Thickness Consideration for Indoor EM Propagation Estimation by SBR Method

    T. Hayashi, H. Shirai

    2016 IEICE General Conference  2016.3 

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  • Dimension Estimation of Polygonal Dielectric Targets From Surface Reflection RCS

    A. Kisumi, H. Shirai

    2015 International Symposium on Antennas and Propagation  2015.11 

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  • Multiple Edge Interaction Effect to Plane Wave Scattering by a Wide and Thick Slit

    M. Shimizu, H. Shirai, R. Sato

    2015 International Symposium on Antennas and Propagation  2015.11 

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  • Ray-mode Conversion Technique Applied To Plane Wave Diffraction By a Thick Slit

    H. Shirai, M. Shimizu

    2015 Korea-Japan Joint Conference on EMT/EMC/BE  2015.11 

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  • Evanescent Modal Effect of a Wide and Thick Slit Diffraction

    M. Shimizu, H. Shirai, R. Sato

    Technical Committee on Electromagnetic Theory, IEICE  2015.10 

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  • Dimension Estimation of Quadrangular Dielectric Cylinder from the Surface Scattering Value

    A. Kisumi, H. Shirai

    Technical Committee on Electromagnetic Theory, IEICE  2015.10 

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  • Far field radiation pattern analysis of an antenna in an automobile

    Z. Zheng, H. Shirai

    Technical Committee on Electromagnetic Theory, IEICE  2015.10 

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  • Estimation of electromagnetic wave propagation using SBR method

    T. Tabata, H. Shirai

    Technical Committee on Electromagnetic Theory (EMT), IEICE  2015.10 

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  • A Study on Radiation Characteristics for Electrically Small Spherical Conducting Shell Antennas

    K. Fujita, H. Shirai

    Technical Committee on Electromagnetic Theory, IEICE  2015.10 

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  • The Radiation Efficiency for Resonant Small Spherical Antennas

    K. Fujita, H. Shirai

    2015 IEICE Society Conference  2015.9 

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  • A Non-Destructive Estimation Method of Permittivity of Dielectric Materials

    A. N. Nguyen, H. Shirai

    2015 International Conference on Electromagnetics in Advanced Applications  2015.9 

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  • A Compact Triple-Band Metamaterial Antenna for WLAN and WiMAX Applications

    H. N. Quang, H. Shirai

    2015 International Conference on Electromagnetics in Advanced Applications  2015.9 

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  • Effect of Curvature of Antipodal Structure on Vivaldi Antennas International conference

    H. B. Chu, H. Shirai, D.C.Chien

    2015 IEEE AP-S Symposium on Antennas and Propagation  2015.7  IEEE

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  • Theoretical Study on the Radiation Efficiency of Electrically Small and Thin Spherical Shell Antennas

    K. Fujita, H. Shirai

    2015 1st URSI Atlantic Radio Science Conference  2015.5 

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  • EM Wave Scattering From Simple Crack Model on Conducting Plane

    R. Sato, H. Shirai

    2015 IEICE General Conference  2015.3 

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  • Balance Condition of Electromagnetic Stored Energy for Spherical Shaped Homogeneous Antennas

    K. Fujita, H. Shirai

    2015 IEICE General Conference  2015.3 

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  • A Study on Complex Permittivity Estimation using Time Domain RCS

    J. Aiso, H. Shirai

    2015 IEICE General Conference  2015.3 

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  • On the Radiation Efficiency of Homogeneous Antennas

    K. Fujita, H. Shirai

    2014 International Symposium on Antennas and Propagation (ISAP 2014)  2014.12 

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  • Analysis of indoor electromagnetic wave propagation using SBR method

    T. Tabata, H. Shirai

    Technical Meeting on Electromagnetic Theory  2014.11 

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  • A Study on Radiation Efficiency and its Excitation Fields for Electrically Small Spherical Antennas

    K. Fujita, H. Shirai

    Technical Meeting on Electromagnetic Theory  2014.11 

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  • Inverse Numerical Calculation to Determine Relative Permittivity of Lossy Dielectric Materials

    A. N. Nguyen, H. Shirai

    Technical Meeting on Electromagnetic Theory  2014.11 

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  • On the Recognition Of the Concave Metal Polygonal Cylinders

    T. Kurabe, H. Shirai

    Technical Meeting on Electromagnetic Theory  2014.11 

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  • Plane wave scattering analysis on V-shape groove (II)

    J. Hayashi, H. Shirai

    Technical Meeting on Electromagnetic Theory  2014.11 

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  • The Radiation Efficiency for Electrically Small Spherical Shell Antennas

    K. Fujita, H. Shirai

    2014 IEICE Society Conference  2014.9 

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  • A Study on Reflection/transmission Characteristics from Two-layered Dielectric Slab

    R. Sato, H. Shirai

    2014 IEICE Society Conference  2014.9 

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  • Analysis and Design of Antipodal Vivaldi Antenna for UWB Applications

    H. B. Chu, H. Shirai, C. D. Ngoc

    2014 IEEE International Conference on Communications and Electronics (ICCE 2014)  2014.8 

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  • Ray-mode conversion method for high frequency scattering analysis

    H. Shirai, R. Sato

    2014 International Conference on Electromagnetics in Advanced Applications (ICEAA)  2014.8 

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  • Perturbation analysis of the TM plane wave scattering from the end-face of a waveguide system

    R. Sato, H. Shirai

    2014 International Conference on Electromagnetics in Advanced Applications (ICEAA)  2014.8 

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  • Radiation directivity of an antenna installed in an automobile

    Z. Zheng, H. Shirai

    2014 Progress In Electromagnetics Research Symposium (PIERS)  2014.8 

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  • Reflection/transmission coefficient for two-layered dielectric slab with internal multiple reflections

    R. Sato, H. Shirai

    2014 IEEE International Symposium on Antennas and Propagation  2014.7 

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  • E polarized plane wave diffraction by a wide and thick slit International conference

    H. Hasegawa, H. Shirai

    2014 IEEE International Symposium on Antennas and Propagation  2014.7  IEEE

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  • 部分的にコーティングされたクラックからの散乱に関する一考察

    佐藤 亮一, 白井 宏

    電気学会電磁界理論研究会  2014.7 

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  • On the Study of Electromagnetic Wave Scattering from Curved Dielectric Surfaces

    J. Aiso, H. Shirai

    Technical Meeting on Electromagnetic Theory  2014.7 

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  • Efficient reflection/transmission coefficient by two-layered dielectric slab for accurate propagation analysis

    R. Sato, H. Shirai

    2014 International Symposium on Electromagnetic Compatibility Tokyo (EMC'14/Tokyo)  2014.5 

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  • The upper limit of the radiation efficiency for electrically small antennas

    K. Fujita, H. Shirai

    2014 IEICE General Conference  2014.3 

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  • Wave proapgation estimation in city area using SBR method

    H. Shirai, T. Maeda

    2014 IEICE General Conference  2014.3 

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  • On the interpolation of EM propagation estimation by SBR method

    K. Arao, H. Shirai

    2014 IEICE General Conference  2014.3 

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  • High frequency scattering analysis of dielectric surfaces - TM incidence case

    A. N. Nguyen, H. Shirai

    2013 Asia-Pacific Microwave Conference (APMC)  2013.11 

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    Electromagnetic TM polarized plane wave scattering by dielectric surfaces is analyzed by high frequency asymptotic method. The scattering field is estimated from the equivalent currents induced by reflected plane wave on the dielectric surface. Effects of material nature, polarization and finiteness of the dielectric bodies are included in a multiple reflection coefficient. A comparison between theoretical estimations and measurement in the case of a rubber cube suggests a strong connection between the thickness of the body and its RCS values.

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  • Plane Wave Scattering Analysis on V-shape Groove

    J. Hayashi, H. Shirai

    Technical Meeting on Electromagnetic Theory  2013.11 

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    An H polarized electromagnetic plane wave scattering by a V-shape groove on the perfectly conducting ground|rn|has been analyzed. Based on assumption that the groove aperture is sufficiently large compared with wavelength,|rn|Geometrical Theory of Diffraction (GTD) has been utilized for obtaining the edge diffracted waves.

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  • E Polarized Plane Wave Diffraction by a Thick Conducting Slit

    H. Hasegawa, H. Shirai, R. Sato

    IEE Technical Meeting on Electromagnetic Theory  2013.11 

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    E polarized electromagnetic plane wave diffraction by a wide and thick slit has been analyzed. High frequency ray-mode coupling analysis has been utilized, and the total diffracted field is considered as a summation of successive modal radiation contribution from the slit aperture due to the original modal excitation by the incident plane wave. The derived results are then compared with those obtained by Kobayashi Potential method, and the corresponding H-mode incidence case.

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  • SBR algorithm for including multiple edge diffracted rays

    T. Maeda, H. Shirai

    IEE Technical Meeting on Electromagnetic Theory  2013.11 

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    For stable high speed wireless communication in urban area, it is necessary to install wireless access base station antennas in proper locations. Specially, for non-LOS (line of sight) propagation in a complex urban environment, edge diffracted ray contribution sometimes plays an important role. Shooting and Bouncing Rays (SBR) method is one of the powerful tool for analyzing high frequency electromagnetic wave propagation estimation including edge|rn|diffracted rays. In this report, new algorithm to include multiple edge diffracted rays has been proposed.

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  • EM Plane Wave Diffraction by a Window Frame Model

    R. Sato, H. Shirai

    IEE Technical Meeting on Electromagnetic Theory  2013.11 

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  • A Compact CPW Fed C-shaped Patch Antenna for Wireless Communication

    H. B. Chu, H. Shirai

    2013 International Conference on Advanced Technology for Communications  2013.10 

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    In this paper, a compact antenna for broadband operation is depicted. A C-shaped patch that based on Chuo University's logo is used to design a monopole radiator. Transmission line theory and the resonator model are adopted to analyze the operating frequencies of the proposed antenna. The bandwidth was enhanced by using the curve of C-shaped patch and CPW feeding method. The proposed antenna was designed and simulated successfully by using HFSS 14. The simulation results show that the antenna has compact size 18.6×17.2 mm2, a good impedance band with range from 3.9 to 7.6 GHz for return loss S11 less than -10 dB. The simulated bandwidth reaches 3.7GHz which is about 72.5% with respect to the center frequency of 5.1 GHz. The antenna can be integrated into wireless communication products such as HIPERLAN/2, IEEE 802.11a/h/j/n, and WiMAX (4.9-5.85GHz).

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  • Electromagnetic wave scattering from dielectric bodies with equivalent current method

    A. N. Nguyen, H. Shirai

    2013 International Conference on Electromagnetics in Advanced Applications (ICEAA)  2013.9 

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    A general three dimensional formulation of high frequency solution for the scattering field of a dielectric body, which is illuminated by a transverse electric polarized plane wave, is presented. Based on the postulated equivalent currents, scattering far field components are derived. Effects of complex permittivity of mat