X 頻段圓極化主動天線

Abstract

單一'雙單元及四單元的圓極化主動天線設計和製作完成.單元之間是以微 帶線並接使其同步並在該微帶線中點置入20歐姆電阻來抑制不須要的模 態.圓極化輻射是以正方去角型微帶貼片天線達成,該型圓級化天線的機制 在本論文將有討論.另外振盪器的設計及其頻率的修正也將論及.天線輻射 場型的得到是分別以旋轉和不旋轉的號角天線所量得.就單一正方去角型 微帶貼片天線其共振輸入阻抗約為180歐姆測得的反射係數達-30dB而圓極 化頻寬為1%.單一'雙單元及四單元的圓極化主動天線測得的有效輻射功率 分別為25mW,210mW及1090mW,達成了空間功率的結合. Single, dual and quartet circularly polarized active antennas were designed and fabricated. Thesynchronization between units was reached by using the strongly coupled lines, which was introduced a20 ohm chip resistor in the middle of the line to suppress the undisired modes. The circularly polarized radiation was achieved by using the corner-truncated microstrip patch antenna. Themechanism of the antenna will be dicussed in this thesis. The design of the oscillator and the modificationof its frequency of oscillation will also be described. The radiation patterns of these antennas were taken by a standard horn antenna with and without spinning, respectively. For the single corner- truncated patch antenna,the input impedance at resonance was around 180 ohm. and the reflection coefficient was measured up to -30 dB. The 3dB circularly polarized bandwidth was about 1%. The effective isotropic radiation power were measured at25mW, 210mW and 1090mW. The spatial power-combining has proven to be achieved.