一种改进了阻抗带宽和低仰角增益的双频圆极化微带天线的设计.PDF

一种改进了阻抗带宽和低仰角增益的双频圆极化微带天线的设计 史雪莹 鄢泽洪 左少丽 ( 西安电子科技大学天线与电磁散射研究所，西安 710071) 摘 要：本文设计了一款可用于卫星通信的圆极化微带天线，采用双层结构实现了双频（1590 MHz，2491 MHz）特性。与用探针直接馈电相比，本文中的天线馈电方式为圆形贴片耦合馈电。仿真结果显示圆极化特 性并获得比较好的驻波比和较高的低仰角增益。对于低频段（1590MHz），阻抗带宽为130MHz，相对带宽为 8.2%。对于高频段（2491MHz ），阻抗带宽为390MHz ，相对带宽达到了 15.7%。在低仰角为 10°时获得的 增益分别为-0.57dB 和 1.49dB，与用探针直接馈电相比，低仰角增益改善了1dB 和 0.6dB。 关键词：层叠微带天线，阻抗带宽，低仰角增益，耦合馈电 A Coupling-Fed Circularly Polarised Microstrip Antenna With Wider Impedance Bandwidth And Higher Low-Elevation Gain Shi Xueying Yan Zehong Zuo Shaoli (Institute of Antenna and EM scattering, Xidian University of China, Xi’an 710071) Abstract: A novel coupling-fed circularly polarized microstrip antenna with wider impedance bandwidth and higher gain at low-elevation is proposed in this paper. Compared with the truncated-corners square patch antenna directly fed by a probe, the proposed antenna s i fed through coupling of a circular patch on the top of the probe. The simulated results verify the circular polarization and show that good VSWR and higher low-elevation gain have been obtained. In the lower band, the obtained impedance bandwidth is 130MHz, or about 8.2% with respect to 1590MHz. In the upper band, the impedance bandwidth is 390MHz, or about 15.7% referenced to 2491MHz. The gain values at 10°low elevation are to be -0.57dB and 1.49dB at two operation frequencies, which are emhanted 1dB and 0.6dB compared with probe directly feeding. Keywords: Stacked microstrip antenna;Impedance bandwidth;Low-elevation gain; Coupling-fed 1 引言 广泛的应用。然而，这种天线的阻抗带宽窄，并且 [5, 6] 低仰角增益低 。利用多点馈电的微带天线可以获