本篇論文主要是在探討如何使用屏蔽技術來提昇行動通訊之效能，並且有效降低人體頭部特定吸收率(SAR)。針對基地台天線，主要是利用阻抗性反射板，將基地台天線之sidelobe反射至mainbeam之方向，因為藉由此種屏蔽方法，可有效降低相鄰sector間overlapping之現象，以降低訊號干擾量，進而提昇通訊品質及增加系統的容量。
　　另一方面則是針對手機，吾人利用導磁薄板之屏蔽技術，除了可有效降低其天線產生之輻射電磁場對於人體頭部特定吸收率，同時不會影響天線本身應有之效能和特性，並且手機美好之外觀也不會因為屏蔽技術之設計而有太大變化。

Applications of shielding techniques are proposed to enhance the antenna performance of mobile communications. The shielding structures for the base station antennas are based on an implementation of resistive plates that tend to reflect the antenna radiation in the side lobes to main beam region, and hence optimize the overlapping coverage between sectors. On the other hand, magnetic materials are employed to design the shielding structures for handset antennas and shells in order to provide good shielding effectiveness for magnetic near fields that were shown to be the major cause of SAR in humane head. Our studies show that with this shielding application the antenna efficiency can be raised while, in the mean time, reducing the SAR induction.

中文摘要 ………………………………………………………………i
英文摘要 ………………………………………………………………ii
致謝 ……………………………………………………………………iii
目錄 ……………………………………………………………………iv
表目錄 …………………………………………………………………vi
圖目錄 …………………………………………………………………vii
第一章 前言 …………………………………………………………1
1.1研究背景 ……………………………………………………………1
1.2研究目的 ……………………………………………………………3
1.3論文大綱 ……………………………………………………………4
第二章 基本理論 ……………………………………………………6
2.1幾何繞射理論 ………………………………………………………6
2.2時域有限差分法 ……………………………………………………7
2.3三次元FDTD理論介紹 ……………………………………………15
2.4 FDTD參數設定要點 ………………………………………………21
2.5計算空間之區分……………………………………………………24
2.6吸收邊界條件………………………………………………………26
第三章 應用阻抗性反射板改善基地台天線效能……………28
3.1阻抗性反射板(R-Card)的原理 …………………………………28
3.2阻抗性反射板(R-Card)阻抗設計 ………………………………30
3.3 GSM基地台 ………………………………………………………37
3.4基地台指向性天線 ………………………………………………38
3.5阻抗性反射板之屏蔽技術 ………………………………………41
3.6量測設備 …………………………………………………………43
3.7量測結果 …………………………………………………………44
第四章 降低頭部SAR之手機天線屏蔽防護技術 …………57
4.1簡介 ………………………………………………………………57
4.2 FDTD頭部模型與手機防護模型的架構…………………………58
4.3手機加上防護時的影響 …………………………………………63
4.4天線效率與增益的比較 …………………………………………65
4.5映象定理對手機天線的影響 ……………………………………67
4.6人體的比例吸收率SAR …………………………………………71
4.7數值模擬結果 ……………………………………………………73
第五章 結論．………………………………………………………90
參考文獻………………………………………………………………92
附錄 FDTD公式推導過程…………………………………………96

〔1〕 C.S. Handel, ”Low Frequency Modification of a Dual Chamber Compact Range,” M.S. Thesis, The Ohio State University,1997.
〔2〕 C.W. Chuang and W.D. Burnside, “An Absorber Fence Concept for Reducing the Undesired Subreflector Scattered Fields form Illuminating Target Zone,” Technical Report732264-2, The Ohio State University ElectroScience Laboratory, March 1997.
〔3〕 I.J. Gupta, K.P. Ericksen and W.D. Burnside, “A Method to Design Blended Rolled Edges for Compact Range Reflectors,” IEEE Trans Antenna Propagation, AP (38):853-861,July 1990.
〔4〕 M.S. Mahmoud, T.-H. Lee and W.D. Burnside, “R-Card Edge Treatment for Compact Range Reflector (2D Case),” Technical Report727723-14, The Ohio State University ElectroScience Laboratory, May 1998.
〔5〕 P.A. Beyerle, I.J. Gupta and E.H. Newman, “Compact Range Reflectors with Resistive Strip Terminations — TM Case,” Technical Report721223-5, The Ohio State University ElectroScience Laboratory, September 1989.
〔6〕 W.I. Pistorius, G.C. Clerici and W.D. Burnside, “A Dual Chamber Gregorian Subreflector System for Compact Range Applications,” IEEE Trans Antenna Propagation, Vol. 37, No. 3, pp305-313, March 1989.
〔7〕 I.J. Gupta, D.G. Brown, W.D. Burnside and W. Lin, “A Serrated Edge Gregorian Subreflector for Dual Chamber Compact Range Systems,” IEEE Trans Antenna Propagation, Vol. 39, No. 8, pp1258-1261, August 1991.
〔8〕 I.J. Gupta and W.D Burnside, “Compact Range Measurement Systems for Electrically Small Test Zones,” IEEE Trans Antenna Propagation, Vol. 39, No. 5, pp.632-638, May 1991.
〔9〕 T-H Lee, R.C. Rudduck and K. M. Lambert, “Pattern Measurements of Reflector Antennas in the Compact Range and Validation with Computer Code Simulation,” IEEE Trans Antenna Propagation, Vol. 38, No. 6, pp.889-895, June 1990.
〔10〕 T-H Lee and W.D. Burnside, “Compact Range Reflector Edge Treatment Impact on Antenna and Scattering Measurements,” IEEE Trans Antenna Propagation, Vol. 45, No. 1, pp57-65, January 1997.
〔11〕 K.S. Yee, ‘’Numerical Solution of Initial Boundary Value Problems Involving Maxwell’s Equations in Isotropic Media, ‘’IEEE Trans. Antennas propagation., 14, 4, pp.302-207, 1966.
〔12〕 ANSI, ANSI/IEEE C95.1-1992： IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 3 KHz to 300 GHz, New York, IEEE, 1992.
〔13〕 K. S. Kunz and R. J. Luebbers, The Finite Difference Time Domain Method for Electromagnetic, Boca Raton, FL, CRC Press, 1993
〔14〕 D.M. Sheen, S. M. Ali, M. D, Abouzahra and L. A. Kong, ‘’ Application of the three-dimensional finite-difference time-domain method to the analysis of plannar microstrip circuits,’’ IEEE Trans. Microwave Theory Tech., Vol. 38, pp.849-857, July. 1990.
〔15〕 K. Umashankar and A. Taflove, ‘’A novel method to analyze electro-magnetic scattering of complex objects, ‘’ IEEE Trans. Electromagn. Compat., Vol. EMC-24, pp 397-405, Nov.1982.
〔16〕 R. J. Luebbers, K. S. Kunz, M. Schneider, and F. Hunsberger, ‘’A finite-difference time-domain near zone to far zone transformation, ‘’ IEEE Trans. Antennas Propagat., Vol. 39, pp. 429-433, Apr. 1991.
〔17〕 K,S. Yee, D. Ingham, and K. Shlager, ‘’ Time domain extrapolation to the far field based on FDTD calculations, ‘’ IEEE Trans. Antennas Propagat., Vol. 39, pp. 410-413, Mar. 1991.
〔18〕 G. Mur, “Absorbing Boundary Conditions for the Finite-Difference Approximation of the Time-Domain Electromagnetic Field Equation, ” IEEE Trans. Electromagnetic Compatibility, EMC-23, pp. 377-382, 1981.
〔19〕 O. M. Ramahi, ‘’Near- and far-field calculation in FDTD simulations using Kirchhoff Surface Integral Representation, ‘’IEEE Trans. Antennas Propagat., Vol. 45, pp. 753-759, Mar. 1997.
〔20〕 A. Taflove and M. E. Brodwin, “Numerical Solution of Steady-Sate Electromagnetic Scattering Problems Using the Time-Dependent Maxwell’s Equation, ” IEEE Trans. on Microwave Theory and Tech., vol. MTT-23, no. 8, pp. 623-630, 1975.
〔21〕 J. D. Jackson, Classical Electrodynamics. New York: Wiley, 1962.
〔22〕 Eiji HANKUI , Tatsuya NAKAMURA, and Osamu HASHIMOTO ,” Low Loss Magnetic Plate Application for Increasing Radiation Efficiency of Cellular Telephones”, IEICE Trans. Vol.E84-C,NO.6 ,pp.814-821, JUNE 2001
〔23〕 E. Hankui and O. Hashimoto, “Increasing the Radiation Efficiency of Cellular Telephone by Controlling the Nearby Electromagnetic Field Around a Human Head, “Microwave and Optical Technology Letters, Vol.29, No. 2, April 20 2001,pp. 104-107.
〔24〕 Paolo Bernardi, Marta Cavagnaro, Stefano Pisa, Emanuele Piuzzi,”Power Absorption and Temperature Elevations Induced in the Human Head by a Dual-Band Monopole-Helix Antenna Phone”, IEEE Trans. Microwave Theory Tech.,Vol.49 ,pp. 2539-2546, DEC. 2001
〔25〕 Michal Okoniewski, Maria A, Stuchly,” A Study of the Handset Antenna and Human Body Interaction”. IEEE Trans. Microwave Theory Tech., Vol. 44, pp.1855-1864, OCT. 1996
〔26〕 Jianqing WANG and Osamu FUJIWARA,’’ Reduction of Electromagnetic Absorption in the Human Head for Portable Telephones by a Ferrite Sheet Attachment’’ . IEICE Trans. Vol.E80-B, NO.12, pp.1810-1815,DEC. 1997
〔27〕 R.Luebbers, L. Chen, T. Uno and S. Adachi, ‘’FDTD Calculation of Radiation Patterns, Impedance, and Gain for a Monopole Antenna on a Conducting Box,’’ IEEE Trans. Antennas Propagat., 40, 12, pp.1577-1583, 1992.
〔28〕 J.G. Maloney and G. S. Smith. ‘’ The Use of Surface Impedance Concepts in the Finite-Difference Time-Domain Method, ‘’IEEE Trans. Antennas Propagat. 40, 1, pp.38-48. 1992.
〔29〕 J. H. Beggs. R. J. Luebbers, K. S. Yee and K. S. Yee and K. S. Kunz, ‘’Finite-Difference Time-Domain Implementation of Surface Impedance Boundary Conditions.’’ IEEE Trans. Antennas Propagat. 40, 1, pp.49-56, 1992
〔30〕 K. S. Yee, K. Shlager and A. H. Chang, ‘’An Algorithm to Implement a Surface Impedance Boundary condition for FTDT, ‘’ IEEE Trans. Antennas Propagat. , 40, 7, pp.833-837, 1992.
〔31〕 J. Toftgard, S. N. Hornsleth , J. B. Andersen, “Effects on Portable Antennas of the Presence of a Person, ” IEEE Trans, Antenna and Propagat., vol.41, no. 6, pp. 739-746 , June 1993.
〔32〕 Chil-Lung, Chiou and Chil-Wen, Kuo, Analysis and Application of Far-Field Transformation in Finite-Difference Time-Domain method,1996.
〔33〕 Hou-Hwa ,Wang and Hsing-Yi ,Chen, Electric Effects Induced In Human Bodies by Pulse Electric Fields, June 1993.
〔34〕 O. M. Ramahi, “Near- and far-field calculation in FDTD simulations using Kirchhoff Surface Integral Representation, “ IEEE Trans. Antennas Propagation., vol. 45, pp. 753-759, May. 1997
〔35〕 Hsien-Lin, Chang and Chil-Wen, Kuo, FDTD Modeling of Common Mode Radiation from Cables,1997.
〔36〕 BALANIS, Antenna theory analysis and design ,second edition ,Wiley,1997.
〔37〕 Zeland Software, Inc., Fidelity user’s manual,Release 3,April 2000.
〔38〕 林振華,電磁場與天線分析使用時域有限差分法(FDTD),全華科技圖書股份有限公司發行,民國八十八年。
〔39〕 Da-Jen Wu and Hsi-Tseng Chou, “Radiation of a Handset Monopole Antenna in the Presence of a Finite Shielding Sheet for the purpose of SAR Reduction”, June 2002.