本論文探討三種不同的天線，分別是超寬頻單極、射頻辨識標籤、及可電氣控制寬頻天線，在論文中將詳細探討這三種天線的設計原理。在第二章裡，超寬頻單極天線具有小型化、3到10GHz的頻寬、全方向性場型的特性，我們並增加電容性的負載來產生於WLAN頻帶上之近10dB的增益衰減。第三章裡，我們設計一款適合在美國使用的UHF 頻帶射頻辨識系統標籤，並闡述設計理論和能量反射係數，經由實體測試，最大的讀取距離為5.5公尺，並以此天線為設計藍圖，設計另外兩款可以在歐洲與日本使用的UHF 頻帶射頻辨識標籤。在第四章裡，我們設計可電氣控制的寬頻天線，在維持3到10GHz的頻寬的條件下，利用PIN二極體和共平面波導至槽線轉接的物理特性，有效改變天線的輻射場型，本章節將討論此天線之增益、場型與設計原理。
本論文的三種天線是使用電磁數值模擬軟體HFSS分析與模擬，再於本校無線通訊與電磁相容技術研發中心之無反射實驗室進行測量，來驗證所設計的天線效能。

In this thesis, two ultrawideband (UWB) antennas with band–notched property, a passive RFID tag antenna, and a wideband pattern reconfigurable antenna are proposed. The UWB antennas are fabricated with double-sided and multi–layered PCB fabrication process, and feature compact size, ultra-wide impedance bandwidth, almost omni-directional patterns, as and gain-suppression properties at the 5GHz-WLAN band. A new UHF RFID meandered tag antenna with tuning stubs is then proposed and experimentally verified. The theoretical power reflection coefficient and the maximum read range are discussed, and the simulated and measured results demonstrate good agreement. Some possible reasons for the discrepancy are discussed. The antenna is found to be insensitive to dielectric loading as well. A wideband pattern reconfigurable antenna with switching pin-diodes is presented in Chapter 4. The reconfigurability relies on changing the signal propagating path along the coplanar waveguide with the help of three pin-diode bias states. The antenna radiation characteristics, gain response, and radiation patterns are examined thoroughly in this thesis.

References
[1] Task group 3a homepage: http://www.ieee802.org/15/pub/TG3a.html
[2] UWB, Forum homepage: http://www.uwbforum.org/
[3] Z. N. Chen, X. H. Wu, N. Yang and M. Y. W. Chia, “Considerations for source pulses and antennas in UWB radio systems,” IEEE Trans. Antennas Propagat., vol. 52, pp. 1739-1748, July 2004.
[4] T. G. Ma and S. K. Jeng, “Planar miniature tapered-slot-fed annular slot antennas for ultra-wideband radios,” IEEE Trans. Antennas Propagat, Vol. 53, pp. 1194-1202, Mar. 2005.
[5] M. Ciattaglia and G. Marrocco, “Approximate calculation of time-domain effective height for aperture antennas,” IEEE Trans. Antennas Propagat., vol. 53, pp. 1054-1061, Mar. 2005.
[6] S. Licul and W. A. Davis, “Unified frequency and time-domain antenna modeling and characterization,” IEEE Trans. Antennas Propagat., vol. 53, pp. 2882-2888, Sep. 2005.
[7] J. McLean, H. Foltz and R. Sutton, “Pattern descriptors for UWB antennas,” IEEE Trans. Antennas Propagat., vol. 53, pp. 553-559, Jan. 2005.
[8] M. Klemm, I. Z. Kov´cs, G. F. Pedersen and G. Tröster, “Novel small-size directional antenna for UWB WBAN/WPAN applications,” IEEE Trans. Antennas Propagat., vol. 53, pp. 3884-3896, Dec. 2005.
[9] H. G.. Schantz, G. Wolence, and E. M. Myszka, “Frequency notched UWB antenna,” in Proc. IEEE UWBST Conf., pp. 214-214, Reston, VA, Nov. 2003.
[10] Y. Kim and D.-H. Kwon, “CPW-fed planar ultra wideband antenna having a frequency band notch function,” Electron. Lett., vol. 40, issue 7, pp. 403-405, April 2004.
[11] T.-G. Ma and S.-K. Jeng, “A planar tapered-slot-fed annular slot antenna with band-notched characteristic for ultra-wideband radios,” IEICE trans. Fundamentals, vol. E88-A, No.9, pp. 2384-2386, Sept. 2005.
[12] Z. N. Low, J. H. Cheong, and C. L. Law “Low cost PCB antenna for UWB application” Antennas Wireless Propaga. Lett., vol. 4, pp. 237-239, 2005.
[13] D. C. Chang, M. Y. Liu, C. H. Lin, “A CPW-fed U type monopole antenna for UWB application,” in IEEE AP-S Int. Symp. Dig., vol. 2A, pp. 512-515, Washington DC, July 3-8 2005
[14] http://www.epcglobalinc.org/index.html.
[15] P.V. Nikitin, S. Lam, K.V.S. Rao, “Low cost silver ink RFID tag antennas,” in IEEE AP-S Int. Symp. Dig., vol. 2B, pp. 353 - 356, Washington DC, July 3-8 2005.
[16] S. Basat, K. Lim, I. Kim, M.M. Tentzeris, J. Laskar, “Design and development of a miniaturized embedded UHF RFID tag for automotive tire applications,” in Proceedings 2005 Electronic Components and Technology Conference., Vol. 1, pp.867 - 870 ,31 May-3 June 2005
[17] H.-W. Son, C.-S Pyo, “Design of RFID tag antennas using an inductively coupled feed,” Electron. Lett., vol. 41, No.18, pp.994 – 996, 1 Sept. 2005
[18] Qing Xianming, Yang Ning, “A folded dipole antenna for RFID,” in IEEE AP-S Int. Symp. Dig., vol.1, pp.97-100, Monterey CA, June 20-25, 2004.
[19] http://www.ti.com/rfid/docs/products/transponders/ transponders.shtml.
[20] K.V.S. Rao, P.V. Nikitin, S.F. Lam, “Antenna design for UHF RFID tags: a review and a practical application,” IEEE Trans. Antennas Propagat. vol. 53, No.12, pp.3870 – 3876, Dec. 2005
[21] P.V. Nikitin, KV.S. Rao, S.F. Lam, V. Pillai, R. Martinez, H. Heinrich, “Power reflection coefficient analysis for complex impedances in RFID tag design,” IEEE Trans. Microwave Theory Tech. vol.53, No. 9, pp.2721 – 2725, Sept. 2005.
[22] J. T. Bernhard, R. Wang, R. Clark, and P. Mayes, “Stacked reconfigurable antenna elements for space based radar applications,” in Proc. IEEE/URSI Antennas Propagat. Soc. Int. Symp., vol. 1, 2001, pp. 158–161.
[23] W. H. Weedon, W. J. Payne, and G. M. Rebeiz, “MEMS-switched reconfigurable antennas,” in Proc. IEEE Int. Symp. Antennas Propagat., vol. 3, 2001, pp. 654–657.
[24] R. N. Simons, C. Donghoon, and L. P. B. Katehi, “Reconfigurable array antenna using microelectromechanical systems (MEMS) actuators,” in Proc. IEEE Int. Symp Antennas Propagat., vol. 3, 2001, pp. 674–677.
[25] M. Boti, L. Dussopt, and J.-M. Laheurte, “Circularly polarised antenna with switchable polarisation sense,” Electron. Lett., vol. 36, no. 18, pp. 1518–1519, Aug. 2000.
[26] F. Yang and Y. Rahmat-Samii, “A reconfigurable patch antenna using switchable slots for circular polarization diversity,” IEEE Microw. Wireless Compon. Lett., vol. 12, no. 3, pp. 96–98, Mar. 2002.
[27] H.Aïssat, L.Cirio, M.Grzeskowiak, J.-M.Laheurte, and OPicon, “Reconfigurable Circularly Polarized Antenna for Short-Range Communication Systems,” IEEE Trans. Microwave Theory Tech, vol. 54, no. 6, Jun. 2006
[28] S. Zhang, G. H. Huff, J. Feng, and J. T. Bernhard, “A Pattern Reconfigurable Microstrip Parastic Array ,” IEEE trans. Antennas Propagat., vol. 52, no. 10, Otc. 2004
[29] D.Peroulis, K.Sarabandi, L. P. B. Katehi,”Design of Reconfigurable Slot Antenna,” IEEE trans. Antennas Propagat., vol. 53, no. 2, Feb. 2005
[30] J. C. Maloney, M. P. Kesler, L.M. Lust, L. N. Pringle, T. L. Fountain, and P. H. Harms, “Switched fragmented aperture antennas,” in Proc. IEEE Antennas Propagat., Soc. Int. Symp., vol. 1, 2000, pp. 310–313.
[31] K. J. Vinoy, K. A. Jose, V. K. Varadan, and V. V. Varadan, “Hilbert curve fractal antennas with reconfigurable characteristics,” in Proc. EEE MTT-S Int. Microw. Symp. Digest, vol. 1, 2001, pp. 381–384.
[32] G. H. Huff, J. Feng, S. Zhang, and J. T. Bernhard, “A novel radiation pattern and frequency reconfigurable single turn square spiral microstrip antenna,” IEEE Microwave Wireless Components Lett.., vol. 13, pp. 57–59, Feb. 2003
[33] E.R. Brown,”RF-MEMS Switches for Reconfigurable Integrated Circuits,” IEEE Trans. Microwave Theory Tech., Vol. 46, No. 11 pp. 1868-80, Nov. 1998
[34] S. Licul and W. A. Davis, “Unified frequency and time-domain antenna modeling and characterization,” IEEE Trans. Antennas Propagat., vol. 53, pp. 2882-2888, Sep. 2005.
[35] Z. N. Chen, X. H. Wu, N. Yang and M. Y. W. Chia, “Considerations for source pulses and antennas in UWB radio systems,” IEEE Trans. Antennas Propagat., vol. 52, pp. 1739-1748, July 2004.
[36] T. G. Ma and S. K. Jeng, “Planar miniature tapered-slot-fed annular slot antennas for ultra-wideband radios,” IEEE Trans. Antennas Propagat., Vol. 53, pp. 1194-1202, Mar. 2005.