臺灣博碩士論文加值系統

本論文首先將針寬頻及高增益等特性設計圓極化天線，提出兩種新穎的設計：倒L形圓極化平面天線和圓柱形探針饋入的寬頻圓極化平面天線。其次，研製適用於 5 GHz 頻帶操作寬頻圓極化之印刷式螺旋形天線；並提出整合型圓極化天線設計，以應用於現有的全球衛星定位系統GPS (1575 MHz)及電子收費系統ETC (5725-5875 MHz) 頻帶操作的車用天線。除此之外，我們針對GPS系統操作的圓極化天線適用於矩形接地面研究，探討接地面的非對稱性對其圓極化特性的變化，其天線結構採用近似正方形圓極化平面天線。對稱性的改變導致圓極化特性變差，當重新調整天線輻射金屬片之長寬比後，天線再度恢復良好的圓極化特性。

This paper proposes two innovative designs for the broadband and high-gain circularly polarized operation, a corner-truncated inverted -L patch antenna and a cylindrical-probe-fed circularly polarized patch antenna using a single probe feed. Next, the broad circularly polarized printed spiral strip antenna for 5 GHz WLAN operation is studied; we also proporse a compact dual-band circularly polarized antenna for GPS/ETC operation on vechicles. In addition, an experimental study of the nearly square circularly polarized microstrip antenna with a rectangular ground plane is presented. The CP antennas are greatly affected by the different side lengths of the rectangular ground plane. To compensate for this effect, the aspect ratio of the nearly square radiating patch should be increased with the increasing aspect ratio of the rectangular ground plane.

文 字 目 錄
頁次
文字目錄 i
圖形目錄 iii
表格目錄 vi

第一章　序論 (Introduction) 1
1.1　概述 1
1.2　文獻探討 4
1.3　內容提要 6

第二章 寬頻圓極化平面天線之設計 (Designs of Broadband Circularly Polarized Planar Antenna) 9
2.1 概述 9
2.2 圓極化天線理論分析 12
2.3 倒L形圓極化平面天線 16
2.4 圓柱形探針饋入的圓極化平面天線 29
2.5 心得與討論 34

第三章 適用於車輛之寬頻圓極化天線 (Broadband Circularly Polarized Antenna for Operation on Vehicles) 36
3.1 概述 36
3.2 適用於5 GHz頻帶操作之寬頻圓極化印刷式螺旋天線 38
3.3 整合型GPS/ETC車用圓極化天線 48
3.4 心得與討論 57

第四章 具有矩形接地面之圓極化天線 (Circularly Polarized Antenna with a Rectangular Ground Plane) 60
4.1 概述 60
4.2 模擬分析與實驗結果 60
4.3 心得與討論 65

第五章 結論 (Conclusions) 67

參考文獻 (References) 70
論文著作表 (Publication List) 74

圖 形 目 錄
頁次
圖2.1 偏極化電磁波傳播(a)線性極化，(b)圓極化。 10
圖2.2 於近似正方形圓極化平面天線結構圖(a>b)。 12
圖2.3 和 相量關係圖。 14
圖2.4 適用於WLAN 操作倒L形圓極化平面天線(a)天線結構圖，(b)輻射金屬片。 17
圖2.5 探針長度d對阻抗匹配變化之史密斯圖。 19
圖2.6 探針長度d對阻抗匹配變化之返回損失圖。 20
圖2.7 等腰三角形的角度α對阻抗匹配變化之史密斯圖。 20
圖2.8 三角形幾何結構對阻抗匹配變化之返回損失圖。 22
圖2.9 倒L形圓極化平面天線返回損失圖。 23
圖2.10 倒L形圓極化平面天線軸比頻率響應圖。 24
圖2.11 倒L形平面天線中心頻率為2442 MHz輻射場型圖(a)垂直與水平極化的線性旋轉場型測量圖，(b)模擬場型圖。 25
圖2.12 倒L形圓極化平面天線增益頻率響應圖。 26
圖2.13 適用5.8 GHz頻帶操作之倒L形圓極化平面天線返回損失圖。 26
圖2.14 適用5.8 GHz頻帶操作之倒L形圓極化平面天線軸比頻率響應圖。 27
圖2.15 適用5.8 GHz頻帶操作之倒L形平面天線的線性旋轉輻射場型測量圖 28
圖2.16 適用5.8 GHz頻帶操作之倒L形圓極化平面天線增益頻率響應圖。 28
圖2.17 圓柱形探針饋入的寬頻圓極化平面天線結構圖。 29
圖2.18 圓柱形探針饋入寬頻圓極化平面天線返回損失圖。 31
圖2.19 圓柱形探針饋入寬頻圓極化平面天線軸比頻率響應圖。 32
圖2.20 圓柱形探針饋入寬頻圓極化平面天線線性旋轉輻射場型測量圖。 33
圖2.21 圓柱形探針饋入寬頻圓極化平面天線增益頻率響應圖。 33
圖2.22 倒L形圓極化平面天線另一實施例。 34
圖3.1 適用5 GHz頻帶操作寬頻圓極化印刷式螺旋天線(a)天線結構圖，(b)側視圖。 39
圖3.2 阻抗匹配電路。 40
圖3.3 傳統螺旋天線輸入阻抗之史密斯圖。 43
圖3.4 螺旋天線植入阻抗匹配之短路金屬之史密斯圖。 44
圖3.5 適用5 GHz頻帶操作寬頻圓極化印刷式螺旋天線返回損失圖。 45
圖3.6 適用5 GHz頻帶操作寬頻圓極化印刷式螺旋天線軸比頻率響應圖。 45
圖3.7 適用5 GHz頻帶操作寬頻圓極化印刷式螺旋天線輻射場型圖(a)垂直與水平極化的線性旋轉場型測量圖，(b)模擬輻射場型圖。 47
圖3.8 適用5 GHz頻帶操作寬頻圓極化印刷式螺旋天線增益圖。 48
圖3.9 整合型GPS/ETC車用圓極化天線結構圖。 49
圖3.10 ETC系統天線植入正方形環狀金屬片結構圖。 52
圖3.11 ETC系統天線植入正方形環狀金屬片3D輻射場型圖(a) w = 20 mm，(b) w = 10 mm，(c)參考天線。 53
圖3.12 返回損失圖(a)GPS系統天線，(b)ETC系統天線。 55
圖3.13 圓極化軸比圖(a)GPS系統天線，(b)ETC系統天線。 56
圖3.14 線性旋轉輻射場型圖(a)GPS系統天線，(b)ETC系統天線。 57
圖3.15 增益頻率響應圖(a)GPS系統天線，(b)ETC系統天線。 58
圖3.16 參考圖3.1圖之螺旋天線設計的流程圖。 59
圖4.1 具有矩形接地面之圓極化天線結構圖。 61
圖4.2 GPS系統天線接地面變化的史密斯圖(a)A = 100 mm，(b) A = 70 mm，(c) A = 60 mm，(d) A = 50 mm。 64
圖4.3 GPS系統天線接地面變化的軸比頻率響應圖。 65
圖4.4 GPS系統天線接地面變化的線性旋轉輻射場型圖。 66

表 格 目 錄
頁次
表1.1 圓極化天線特性比較。 6
表2.1 以3 dB軸比定義圓極化頻寬與參數Q、a/b和t/λ參考表。 15
表2.2 角度α對圓極化特性之變化表，阻抗頻寬以1.5:1 VSWR定義，CPBW以3 dB軸比定義。 21
表3.1 GPS/ ETC操作之圓極化特性的量測值。阻抗頻寬以10 dB 返回損失定義，CP 頻寬以 3 dB軸比定義。 54
表4.1 具有矩形接地面的近似正方形平面天線CP 輻射特性的比較；W = 44.5 mm，B = 100 mm。阻抗頻寬以2:1 VSWR定義，且 CP 頻寬以3 dB 軸比定義，fc 是最小軸比之頻率。 62
表5.1 寬頻平面天線圓極化特性。 68

參 考 文 獻
(References)

[1]Y. T. Lo and R. Q. Lee, “Simple design formulas for circularly polarized microstrip antennas,” IEE Proc., vol. 135, Pt. H, No. 3, pp. 213-215, 1988.
[2]W. F. Richards, Y. T. Lo , and P. Simon, “Design and theory of circularly polarized microstrip antennas,” IEEE Antennas Propagat. Soc. Int. Symp. Dig., vol. 1, pp. 117-120, 1979.
[3]W. F. Richards, Y. T. Lo, and D. D. Harrison, “An improved theory for microstrip antenna and applications,” IEEE Trans. Antennas Propagat., vol. 29, pp. 38-46, 1981.
[4]T. W. Chiou and K. L. Wong, “Single-layer wideband probe-fed circularly polarized microstrip antenna,” Microwave Opt. Technol. Lett., vol. 25, pp. 74-76, 2000.
[5]N. Herscovici, “A wide-band single-layer patch antenna,” IEEE Trans Antennas Propagat., vol. 46, pp. 471-474, 1998.
[6]C. L. Mak, K. M. Luk, K. F. Lee and Y. L. Chow, “Experimental study of a microstrip patch antenna with an L-shaped probe,” IEEE Trans. Antennas Propagat., vol. 48, pp. 777-783, 2000.
[7]G. A. E. Vandenbosch and A. R. Van de Capelle, “Study of the capacitively fed microstrip antenna element,” IEEE Trans. Antennas Propagat., vol. 42, pp. 1648-1652, 1994.
[8]K. L. Wong and T. W. Chiou, “Broadband single-patch circularly polarized microstrip antenna with dual capacitively-coupled feeds,” IEEE Trans. Antennas Propagat., vol. 49, pp. 41-44 , 2001.
[9]W. H. Hsu and K. L. Wong, “A dual-capacitively-fed broadband patch antenna with reduced cross-polarization radiation,” Microwave Opt. Technol. Lett., vol. 26, pp. 169-171, 2000.
[10]W. H. Hsu and K. L. Wong, “Broadband probe-fed patch antenna with a U-shaped ground for cross-polarization reduction,” IEEE Trans. Antennas Propagat., vol. 50, pp. 352-355, 2002.
[11]F. S. Chang and K. L. Wong, “A broadband probe-fed patch antenna for DCS base station,” Microwave Opt. Technol. Lett., vol. 30, pp. 341-343, 2001.
[12]F. S. Chang and K. L. Wong, “A broadband probe-fed planar patch antenna with a short probe pin and a conducting cylinder transition,” Microwave Opt. Technol. Lett., vol. 31, pp. 282-284, 2001.
[13]S. Fuyama, “Electronic toll collection system,” U.S. Patent No. 6509843 B1, Jan. 2003.
[14]R. C. Johnson, Antenna Engineering Handbook, New York: McGraw-Hill, 1993, Chap. 14.
[15]H. Nakano, K. Nogami, S. Arai, H. Mimaki and J. Yamauchi, “A spiral antenna backed by a conducting plane reflector,” IEEE Trans. Antennas Propagat., vol. 34, pp. 791-796, 1986.
[16]J. D. Kraus, Antennas, New York: McGraw-Hill, 1988, Chap. 7.
[17]H. E. King and J. L. Wong, “Characteristics of 1 to 8 wavelength uniform helical antennas,” IEEE Trans. Antennas Propagat., vol. 28, pp. 291-296, 1980.
[18]H. Nakano Y. Samada and J. Yamauchi, “Axial mode helical antenna,” IEEE Trans. Antennas Propagat., vol. 34, pp. 1143-1148, 1986.
[19]Y. Ojiro, T. Hiraguri and K. Hirasawa, “A monopole-fed circularly polarized loop antenna,” in 1998 IEEE Antennas Propagat. Soc. Int. Symp. Dig., pp. 810-813.
[20]H. Nakano, S. Okuzawa, K. Ohishi, H. Mimaki, and J. Yamauchi, “A Curl antanna,” IEEE Trans. Antennas Propagat., vol. 41, pp. 1570-1575, 1993.
[21]F. Yang and Y. Rahmat-Samii, “A low-profile circularly polarized curl antenna over an electromagnetic bandgap (EBG) surface,” Microwave Opt. Technol. Lett., vol. 31, pp. 264-267, 2001.
[22]N. Paulin, H. Rebelo, F. Pires, I. Ventim Neves, J. Goes and A. Steiger-Garcao, “Design of a spiral-mode microstrip antenna and matching circuitry for ultra-wide-band receivers,” in 2002 IEEE Circuits and Systems Soc. Int. Symp. Dig., vol. 3, pp. 875-878.
[23]S. Mano and T. T. Katagi, “A method of measuring amplitude and phase materials ,” Trans. IECE Japan, vol. 68, pp. 441-450, 1991.
[24]K. L. Wong, W. S. Hsu and C. K. Wu, “Single-feed circularly polarized microstrip antenna with a slit,” Microwave Opt. Technol. Lett., vol. 18, pp. 191-193, 1982.
[25]J. Y. Wu and K. L. Wong, “Two integrated stacked patch antennas for DCS/WLAN dual-band operations,” Microwave Opt. Technol. Lett., vol. 30, pp. 134-136, 2001.
[26]J. Y. Wu, J. S. Row and K. L. Wong, “A compact dual-band microstrip patch antenna suitable for DCS/GPS operations,” Microwave Opt. Technol. Lett., vol. 29, pp. 410-412, 2001.
[27]J. Ollikainen, M. Fischer and P. Vainikainen, “Thin dual-resonant stacked shorted patch antenna for mobile communications,” Electron Lett., vol. 35, pp. 437-438, 1999.
[28]K. L. Wong, Compact and broadband microstrip antennas, Wiley, New York, 2000, Chap. 5.
[29]S. Aoghanian and L. Shafai, “Control of microstrip antenna radiation characteristics by ground size and shape,” IEE Proc.-Microw. Antennas Propagat., vol. 145, pp. 207-212, 1998.
[30]T. W. Chiou and K. L. Wong, “Designs of compact microstrip antennas with a slotted ground plane,” in 2001 IEEE Antennas Propagat. Soc. Int. Symp. Dig., pp. 732-735, 2001.
[31]S. D. Elliott and D. J. Dailey, Wireless Communications for Intelligent Transportation Systems, Boston, MA: Artech House, 1995.
[32]J. C. Louvigne and A. Sharaiha, “Synthesis of printed quadrifilar helical antenna,” Electron. Lett., vol. 37, pp. 271-272, 2001.
[33]A. A. Chatzipertros and S. Licul, “Folded helix antenna design,” U.S. Patent No. 6229499 B1, Jan. 2001.
[34]A. Sharaiha and C. Terret, “Parametrical study of printed quadrifilar helical antennas with central dielectric rods,” Microwave Opt. Technol. Lett., vol. 20, pp. 249-255, 1999.
[35]http://www.xaht.com/sccs.asp, Haitian antenna