本論文研製一寬頻共平面波導饋入之圓形單偶極天線，天線結構主要由共平面波導傳輸線與圓形金屬片所組成，藉由在共平面波導傳輸線接地面上設計一類似散佈式匹配網路性質的漸進式接地金屬面結構，大幅提升天線的阻抗頻寬，並改善天線在無漸進式結構下高頻輻射場型不佳的問題，然而此項設計卻造成天線在低頻之cross-polarization增加。本文提出在漸進式接地金屬面上加入週期槽線結構，有效地改善天線在低頻操作時，高cross-polarization之缺點，並且使天線於高頻操作時，仍保有輻射場型之全指向性。此天線結構模擬與量測結果相當一致，在電壓駐波比 的條件下，操作頻帶可由810MHz至5.87GHz，阻抗頻寬高達151%，此頻帶涵蓋了GSM、DCS、PCS、PHS、3G、WLAN、WIFI及WiMAX等無線通訊頻段，在上述操作頻帶內的輻射場型皆有良好的全指向性。在結構上，此天線為單面結構，易於印刷製作，可應用於上述頻帶之無線通訊系統上。

A ultra-broadband, planar, circular monopole antenna (PCMA) fed by coplanar waveguide (CPW) structures is demonstrated. The CPW configuration permits easy integration with the uniplanar monolithic integrated circuits/monolithic microwave integrated circuits. Two modifications on the CPW ground plane are applied to improve the impedance bandwidth and radiation characteristics of the CPW-fed PCMA. First, the edges around the circular monopole are tapered to drastically increase the impedance bandwidth. Plus, the antenna gain is increased at the lower frequencies of the band. Second, the tapered edges are corrugated with rectangular gratings to significantly improve the radiation patterns, particularly at the frequencies around the higher band edge. The demonstrated CPW-fed PCMA features an over 151% VSWR=2 fractional bandwidth and satisfactory radiation characteristics over the whole band.

[1]Stutzman, W.L., and Thiele, G.A., “Antenna theory and design,”(John Wiley & Sons, New York, USA, 1998, 2nd edu.)
[2]M.I. Aksun, S.L. Chuang, and Y.T. Lo, “Coplanar waveguide-fed microstrip antennas,”Microwave Opt. Tech. Lett., pp.292-295, Apr. 1991.
[3]W. Menzel and W. Grabherr, “A microstrip patch antenna with coplanar feed line,”IEEE Microwave Guide Lett., pp.340-342, Jan. 1991.
[4]S.M. Deng, M.D. Wu, and P. Hsu, “Analysis of coplanar waveguide-fed microstrip antenna,”IEEE Trans. Antennas Propagat., pp.734-737, 1995.
[5]S. Sierra-Garcia and J.J. Laurin, “Study of a CPW inductively coupled slot antenna,”IEEE Trans. Antennas Propagat., pp.58-64, 1999.
[6]J.C. Batchelor, R.J. Langley and H. Endo, “On-glass mobile antenna performance modeling,”IEE Proc. Microwave Antennas Propagat., vol.148, no.4, August 2001.
[7]A.J. Ramzi and E.K. Walton, “Numerical modeling of on-glass conformal automobile antennas,”IEEE Trans. Antennas Propagat., vol.46, no.6, Jun. 1998.
[8]S.H. Choi, J.K. Park, S.K. Kim and J.Y. Park, “A New Ultra-Wideband antenna for UWB Applications,”Microwave Opt. Tech. Lett., vol.40, no.5, March 2004.
[9]K. Chung, T. Yun and J. Choi, “Wideband CPW-fed Monopole Antenna with Parasitic Elements and Slots,”Electronics Lett., vol.40, no.17, August 2004.
[10]S.Y. Suh, W.L. Stutzman and W.A. Davis, “A New Ultrawideband Printed Monopole Antenna: The Planar Inverted Cone Antenna (PICA),”IEEE Trans. On Antennas and Propagat., vol.52, no.5, May 2004.
[11]C.P. Wen, “Coplanar waveguide : A surface strip transmission line suitable for nonreciprocal gyromagnetic device application,”IEEE Transactions on Microwave Theory and Techniques, vol.17,pp.1087-1090, Dec. 1969.
[12]K. Tilley, X.D. Wu and K. Chang, “Coplanar waveguide fed coplanar strip dipole antenna,”Electron. Lett., pp.176-177, 1994.
[13]W. Wang, S.S. Zhong and S.B. Chang, “A novel wideband coplanar-fed monopole antenna,”Microwave Opt. Tech. Lett., vol.43, pp.50-52, 2004.
[14]G. Dubost and S. Zisler, “Antennas a Large Band,”New York : Masson, pp.128-129, 1976.
[15]Anon., “FCC First Report and Order on Ultra-Wideband Technology,”February. 1998.
[16]A. Kerkhoff and H. Ling, “Design of a Planar Monopole antenna for Use with Ultra-Wideband(UWB) Having a Band-Notched Characteristic,”IEEE Int’l Symposium on Antennas and Propagat., vol.1, pp.830-833, Jun. 2003.
[17]H. Schantz, L. Fullerton, “The Diamond Dipole: A Gaussian Impulse antenna,”IEEE Int’l Symposium on Antennas and Propagat., vol.4, pp.100-103, July. 2001.
[18]M.J. Ammann, “Square planar monopole antennas,”IEE Publication, no.461, pp.37-40, 1999.
[19]P.V. Anob, K.P. Ray and Girish Kumar, “Wideband orthogonal square monopole antennas with semi-circular base,”IEEE Antennas and Propagat. Society, vol.3, pp.294-297, 2001.
[20]M.J. Ammann, “Control of the impedance bandwidth of wideband planar monopole antennas using a beveling technique,”Microwave Opt. Technol. Lett., vol.30, pp.229-232, Aug. 2001.
[21]K.L. Wong, C.H. Wu and S.W. Su, “Ultrawide-Band Square Planar Metal-Plate Monopole Antenna With a Trident-Shaped Feeding Strip,”IEEE Trans. Antennas Propagat., pp.1262-1269, 2005.
[22]A. Kerkhoff, H. Ling, “The Design and Analysis of Miniaturized Planar Monopoles,”IEEE Int’l Symposium on Antennas and Propagat., vol.4, pp.30-33, Jun. 2002.
[23]A. Kerkhoff, R.L. Rogers and H. Ling, “Design and Analysis of Planar Monopole Antennas Using a Genetic Algorithm Approach,”IEEE Trans. Antennas and Propagat., 2002.
[24]S.Y. Suh, Warren L. Stutaman and William A. Davis, “A new ultrawideband printed monopole antenna: the Planar Inverted Cone Antenna (PICA),”IEEE Trans. Antennas Propagat., vol.52, no.5, pp.1361-1365, May. 2004.
[25]S.W. Qu, J.L. Li and Quan Xue, “A Band-Notched Ultrawideband
Printed Monopole Antenna,”IEEE Antennas and wireless Propagat. Lett., vol.5, 2006.
[26]W.S. Lee, D.Z. Kim, K.J. Kim and J.W. Yu, “Wideband Planar Monopole Antennas With Dual Band-Notched Characteristics,”IEEE Trans. On Microwave Theory And Techniques, vol.54, no.6, Jun. 2006.
[27]A. Kerhoff and H. Ling, “A Parametric Study of Band-Notched UWB Planar Monopole Antenna,”IEEE Int’l symposium on Antennas Propagat., vol.2, pp.1768-1771, July 2004.
[28]X.L. Liang, S.S. Zhong and F.W. Yao, “Compact UWB Tapered-CPW-fed Planar Monopole Antenna,”Electron Lett., 2005.
[29]Yangwoon Roh, Kyungho Chung, “Design of a Microstrip-fed Ultra- wideband Monopole Antenna Having Band Rejection Characteristic,”Electronics Lett., 2005.
[30]X.L. Liang, S.S. Zhong, W. Wang and F.W. Yao, “Printed annular monopole antenna for ultra-wideband applications,”Electronics Lett., vol.42, no.2, Jan. 2006.
[31]Nan Wei Chen, C.T. Chuang and J.W. Shi, “A W-Band Linear Tapered Slot Antenna on Rectangular-Grooved Silicon Substrate,”IEEE Antennas and Wireless Propagat. Lett., vol.6, 2007.