本論文提出可以改變天線「輻射場型」與「極化方向」的設計方法。首先，天線「輻射場型」的改變可利用高導磁係數的鐵磁性材料設計於天線，以材料本身的特性、形狀來改變原本天線的「輻射場型」。先以簡單的單極天線為研究對象，採取平面無孔洞、單孔洞及多孔洞之鐵磁性材料，探討其對天線之影響，發展出天線之一側放置鐵磁性材料，合併成為「磁性天線」；對於天線之一側放置有孔洞之鐵磁性材料者，合併成為「孔洞磁性天線」。由研究結果得知，對於中心頻率操作在UHF頻段(860-960MHz)之無線識別系統(RFID)，「磁性天線」加入適當的鐵磁性材料，的確可以增加reader天線2.26dBi的增益值，以及reader 和 tag之間的讀取距離，約可增加70%的傳輸距離。
其次，天線「極化方向」的改變是利用二極體開關來設計，使天線可以調整其極化方向。以貼片天線為主體，加入環形槽孔，在槽孔上以間隔30°的方式擺放二極體。藉由相鄰的六顆二極體導通，調整電場極化方向角度分別為0°、30°、60°、90°、120°、150°等六種，來達到線性極化波的極化方向切換，使得單一天線具有接收不同極化方向訊號的效果。由結果發現，雖與模擬數據有所差異，但整體趨勢還是相當吻合，也證明了設計的正確性。
兩種改變天線特性的方式於模擬與實測結果均顯示，其架構簡單、調整容易，在實用性上，均能依不同狀況調整使其達到最佳的收訊效果，亦為本研究主要之目的。

In this thesis, we propose the two design method of antenna, one is reconfigurable of radiation pattern and another one is reconfigurable of polarization. First, the radiation pattern reconfigurability is realized straightforwardly with an employment of a detached magnetodielectric slab placed in the vicinity of the antenna structure. We determine the monopole antenna which is simple to research. Then, discuss on using magnetodielectric slab placed in the vicinity of the antenna structure, like non-porous, single hole, porous slab. Therefore, we define ‘magnetic antenna”. The antenna structure with single hole or porous slab, we define ‘porous magnetic antenna”. As above results, through the use of a magnetodielectric material on the back of the RFID reader antenna, the antenna gain is increased 2.26dBi. This enhancement has increased the operational range behind the the antenna by nearly 70% for far-zone reading.
Secondly, we use diode to design reconfigurable of polarization, which able to adjust antenna. We use a circular patch antenna with a ring slot on it. On the ring slot, diode switches are placed at 30° interval. We propose a design of polarization diversity antenna which is able to generate six Lps st a 30° interval (0°, 30°, 60°, 90°, 120°, 150°) with the same antenna characteristics due to symmetry in geometry of the antenna. Measured results are in good agreement with the simulated, proving the correctness of our design.
Two reconfigurable of antenna methods shown in simulated and measured results, the demonstrated antennas own a low-cost, adjust-easy are expected to find application in noise or interference suppression for the mobile devices in different environment. It’s the purpose on this research.

摘　要……………………………………………………………………………….I
Abstract……………………………………………………………………………II
致 謝………………………………………………………………………………III
目 錄………………………………………………………………………………IV
圖表索引...........................................................VI
第一章 緒論 1
1.1 研究動機 1
1.2 研究背景 2
1.3 研究目的與方法 3
1.4 論文章節簡介 5
第二章 天線基本理論介紹 6
2.1 應用於通訊領域常見的天線種類 6
2.2 微帶天線之設計 7
2.3 鐵磁性材料影響天線之機制 9
2.4 貼片天線基本理論與結構之分析 15
第三章 輻射場型切換天線……………………………………………………… 20
3.1 鐵磁性材料介紹 20
3.2 鐵磁性材料應用於單極天線 21
3.2.1 磁性天線簡介 26
3.2.2 磁性天線模擬、分析與量測結果 27
3.2.3 孔洞磁性天線簡介 37
3.2.4 孔洞磁性天線設計、模擬與量測結果 39
3.3.5 「磁性天線」與「孔洞磁性天線」之比較 43



第四章 磁性天線於通訊領域之應用 46
4.1 2.4GHz共平面波導(CPW)之應用 46
4.1.1 天線架構與方法…………………………………………………46
4.1.2 天線的模擬與量測 48
4.1.3 結果與討論 52
4.2 UHF頻段 RFID Reader之應用 52
4.2.1 RFID系統介紹 ………………………………………………… 52
4.2.2 可延伸讀取距離之RFID Reader 53
4.2.3 實測讀取性能研究 56
4.2.4 結果與討論 57
第五章 線性極化方向切換天線 58
5.1 二極體開關切換天線之設計 58
5.1.1 設計流程 58
5.1.2 二極體參數萃取 59
5.1.3 參數探討 62
5.2 二極體開關切換天線之實作 70
5.2.1 偏壓電路與天線之實作 70
5.2.2 二極體參數探討 84
5.2.3 結果與討論 89
第六章 結論 91
6.1 結論 91
6.2 未來展望 92
References... 93

[1].Warren L. Stutzman and Gary A. Thiele, Antenna Theory and Design, 2nd edition, John Wiley& Sons, United States, pp.395-424, 1998.
[2].Pozar, D.M., “Microstrip Antennas”, Proceedings of the IEEE, vol. 80, pp. 79-91, Jan. 1992.
[3].Seong Youp Suh, Warren L. Stutzman, and William A. Davis“ A new ultra wideband printed monopole antenna：the planar inverted cone antenna（PICA）” Antennas and Propagation, IEEE Transactions on, Volume: 52, pp. 1361-1364, Issue: 5, May 2004.
[4].C. R. Rowell and R. D. Murch, “A compact PIFA suitable for dualfrequency 900/1800-MHz operation,” IEEE Trans. Antennas Propagat., vol. 46, pp. 596-598, Apr. 1998.
[5].David M. Pozar, Microwave Engineering, 3rd edition, John Wesley& Sons, United States, pp.547-601, 2005.
[6].W. Xijin, Z. Hongmei, N. Yanjuan, and Z. Yong, “MEMS dual-band frequency and polarization reconfigurable microstrip antenna,” Second IITA International Conference on Geoscience and Remote Sensing, pp. 36-37, 2010.
[7].Fujimoto et al., “Antenna apparatus employing a ceramic member mounted on a flexible sheet, United States Patent, pp. 61-62, 2011.
[8].S. D. Padhi, N. C. Kamakar Sr., C. L. Law, and S. Aditya Sr., "A dual polarized aperture coupled circular patch antenna using a C-shaped coupling slot," IEEE Transactions Antennas and Propagation, Vol. 51, No. 12, pp. 50-51, December 2003.
[9].S. C. Gao, L. W. Li, M. S. Leong, and T. S. Yeo, "Dual-polarized slot-coupled planar antenna with wide bandwidth," IEEE Transactions Antennas and Propagation, Vol. 51, No. 3, pp. 21-23, March 2003.
[10].L. Habib, G. Kossiavas, and A. Papiernik, “Cross-shaped patch with etched bars for dual polarization,” Electronic Letters, Vol. 29, No. 10, pp. 120-122, May 1993.
[11].M. Yamazaki, E. T. Rahardjo, and M. Haneishi, “Construction of a slot-coupled planar antenna for dual polarization,” Electronic Letters, vol. 30, No. 22, pp. 123-126, October 1994.
[12].C. Y. Huang, K. L. Wong, “Stripline-fed printed square spiral slot antenna for circular polarization,” Electronic Letters, Vol. 34, No. 24, pp. 65-69, November 1998.
[13].K. L. Wong, C. C. Huang, and W. S. Chen, “Printed ring slot antenna for circular polarization,” IEEE Transactions On Antennas And Propagation, Vol. 50, No. 1, pp. 205-208, January 2002.
[14].L. P. Chi, S. S. Bor, S. M. Deng, C. L. Tsai, P. H. Juan, and K.W. Liu, “A wideband wide-strip dipole antenna for circularly polarized wave operations,” Progress In Electromagnetics Research, PIER, pp. 100, 2010.
[15].S. M. Deng, C. L. Tsai, M. F. Chang, S. S. Bor, “A study on the non-uniform rectangular-ring slot antenna for broadband circular polarization operations,” Journal of Electromagnetic Waves and Applications, Vol. 24, No. 4, pp. 567-568, Number 2010.
[16].C. L. Tsai, S. M. Deng, C. H. Tseng, and S. S. Bor, “Antennas with two shorted rectangular ring slots coupled by microstrip line for the opposite sense CP in the wide-band operations,” Journal of Electromagnetic Waves and Applications, vol. 23, No. 10, pp. 631-636, Number 2009.
[17].C. L. Tsai, S. M. Deng, C. H. Tseng, and S. S. Bor, “A shorted square-ring slot antenna with a branched slot for the 1575 MHz and 2.4 GHz dual-band operations,” Microwave Optical Technology Letters, Vol. 51, No. 2, pp. 101-103, February 2009.
[18].Y. Sim, J. Kim, J. Woo, “Dual-feed Circular Polarization Folded Microstrip Antenna,” Antennas, Propagation and EM Theory, pp. 865-870, Number 2008.
[19].C. L. Tsai, S. M. Deng, T. W. Chen, and L. W. Liu, “Circularly polarized dielectric resonator-loaded circular microstrip patch antennas for WLAN 2.4 GHz applications,” Microwave And Optical Technology Letters, Vol. 51, No. 6, pp. 553-563 June 2009.
[20].X. M. Qing, and Y. W. M. Chia, “Circularly polarized circular ring slot antenna fed by stripline hybrid coupler,” Electronic Letters, vol. 35, No. 25, pp. 131-134, December 1999.
[21].M. Singh, A. Basu, and S. K. Koul, “Switchable frequency bands microstrip antennas,” Antenna Technology, pp. 128-138, 2009.
[22].J. S. Row, and T. Y. Lin, “Frequency-reconfigurable coplanar patch antenna with conical radiation,” IEEE Antennas And Wireless Propagation Letters, Vol. 9, pp. 720-723 2010.
[23].Y. J. Sung, “Reconfigurable patch antenna for polarization diversity,” IEEE Transactions On Antennas And Propagation, Vol. 56, No. 9, pp. 159-165September 2008.
[24].W. S. Yoon, J. W. Baik, H. S. Lee, S. Pyo, S. M. Han, and Y. S. Kim, “A reconfigurable circularly polarized microstrip antenna with a slotted ground plane,” IEEE Antennas And Wireless Propagation Letters, Vol. 9, pp. 361-364 2010.
[25].蕭賀臻， “The effect of the board size on the characteristic of patch antenna”，長庚大學電子工程研究所碩士論文，, pp.1-5, 2003.
[26].D. M. Pozar, “Microstrip antennas”, Proceedings of the IEEE, Volume: 80, Issue: 1, pp. 79–91, Jan. 1992.
[27].“IE3D”, Zeland Software, Inc.
[28].Constantine a. Balanis, “Antenna theory analysis and design”, Wiley, New York, pp. 807-815, 1938.
[29].Tapan K. Sarkar, Sadasiva M. Rao, Antonije R. Djordjevic, “Electromagnetic Scattering and Radiation from Finite Microstrip Structures” , Microwave Theory and Techniques, IEEE Transactions On Antennas And Propagation, Volume 38, Issue 11, pp.1568–1575, Nov. 1990.
[30].C. A. Balanis, Antenna Theory Analysis and Design, 2nd ed., United States of America, John Wiley & Sons, pp. 235-241, 1997.
[31].Ｗ. L. Stutzman and G. A. Thiele, Antenna Theory and Design, 2nd ed., John Wiley and Sons, pp. 617-625, 1998.
[32].Z-T Guan, S-W Zhang, Y-L Liu, R-G Yang, “Research of Reflection Characteristics of Magnetic Boundary”, Journal of Southwest Jiaotong University, vol. 39, No. 5, pp.699-702, 2004.
[33].李德才，“磁性液體理論及應用”，科學出版社，, pp.318-321, 2005.
[34].HFSS 11, Ansoft Corporation (ANSYS) [Online]. Available: www.ansoft.com
[35].Pozar, D. M., Microwave Engineering, 2nd edition, Wiley, New York, pp. 309-316, 1998.
[36].Balanis, C. A., Antenna Theory, Analysis and Design, 2nd edition, Wiley, New York, pp. 315-364, 1997.
[37].Wen-Cheng Lai, Dong-Lin Miao, Ching-Wen Hsue, “Effect of Magnetic Layer on Radiation Characteristics of Monopole Antenna”, 2009 ICONIC conference, Taipei, Taiwan, pp.255-258, 2009.
[38].David M. Pozar, Microwave Engineering, 3rd edition, John Wesley& Sons, United States, pp. 61-64, 2005.
[39].David K. cheng, Field and Wave Electromagnetics, 2nd edition, Addison-Wesley, New York, pp.643-712, 1992.
[40].Hsue, C-W. and Lai, W-C., RFID Reader Range Extension using Magnetodielectric Material, 2012 3rd International Innovation and Invention Conference (IIIC), Taipei, Taiwan, pp. 95-96, 2012.
[41].Lai, W-C., Sun, A-C., Chen, N-W., and Hsue, C-W., Gain enhancement of planar monopole with magnetodielectric material, Progress In Electromagnetics Research C, Vol. 21, pp. 179-190, 2011.
[42].張烈豪， “Reconfigurable Circular Patch and Ring Slot Antennas Using Diode Switches”，長庚大學電子工程研究所碩士論文，, pp.9-81, 2011.