許博文臺灣大學：電信工程學研究所蘇哲穎Su, Che-YingChe-YingSu2007-11-272018-07-052007-11-272018-07-052004http://ntur.lib.ntu.edu.tw//handle/246246/58574微帶天線在現代的通訊系統應用中扮演著非常重要的角色。然而我們都知道,微帶天線受到窄頻寬和極化程度的限制。 在本論文中,為了改進頻寬和極化程度,我們提出了一結合T形饋入線和循序旋轉技巧的共面波導饋入之圓極化陣列天線。 我們實現了使用循序旋轉和未使用循序旋轉的1×2和2×2陣列天線。從模擬與量測的結果當中,我們可以看到使用循序旋轉技巧的1×2和2×2陣列天線,在頻寬上有很明顯的提升。Microstrip patch antennas play an important role in wide application in modern communication systems. However, it is well known that microstrip antennas are limited in bandwidth and polarization purity. In this thesis, in order to increase the bandwidth and polarization purity, a wide bandwidth CPW-fed circularly polarized patch array is proposed by combining the T-shaped feeding structure and the principle of sequential rotation technique. The simulated and measured axial ratios, return losses , and radiation patterns are presented for 1×2 and 2×2 arrays with and without sequential rotation. Significant increases in the axial ratio and return loss bandwidths are found in the array with sequential rotation.Chapter 1 Introduction••••••••••••••1 1.1Motivation and LiteratureSurvey •••••••••••1 1.2Chapter Outlines •••••••••••••••••••4 Chapter 2 Circularly Polarized Patch Antenna•••••••6 2.1Feeding Structures••••••••••••••••••6 2.2Mode Analysis Based on Cavity Model •••••••••7 2.3Necessary condition for circular polarization radiation.......................................11 Chapter 3 Design of Circularly Polarized Patch Antenna Fed by CPW •••••••••••••••••••••25 3.1Influence of CPW-Fed Structure on Circularly Polarized Patch Antenna ••••••••••••••••••••25 3.2Design of Circularly Polarized Patch 1D Array Fed by CPW •26 3.3Design of Circularly Polarized Patch 2D Array Fed by CPW •28 Chapter 4 Design of CPW-Fed Circularly Polarized Patch Antenna Utilizing Sequentially Rotated Techniqu•••••38 4.1The Principle of Sequential Rotation•••••••••38 4.2Design for 1D Array •••••••••••••••••43 4.3Design for 2D Array •••••••••••••••••44 Chapter 5 Conclusion••••••••••••••60 Appendix A Equivalent Circuit Model for Single-Fed Patch Radiator with a Perturbation ••••••••••61 Appendix B Formulas for Calculating the Axial Ratio of a CP Wave ••••••••••••••••••••70 References •••••••••••••••••••••••76608293 bytesapplication/pdfen-US天線共面波導循序旋轉圓極化arrayCPWpatchcircularly polarizedsequential rotationthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/58574/1/ntu-93-R91942058-1.pdf