一种小型化宽带圆极化微带天线的设计

设计并加工了一种采用同轴背馈方式馈电的小型化宽带圆极化微带天线。针对单点馈电微带天线轴比带宽窄的问题，通过增加馈电网络对天线辐射贴片进行双点馈电以展宽轴比带宽，得到了良好的效果。馈电网络根据带状线理论设计，利用U形接地板巧妙地实现了宽带天线的结构小型化。通过对辐射贴片的双点馈电获得了令人满意的电压驻波比带宽和良好的圆极化性能。通过仿真和实际测试表明，该天线VSWR≤2的带宽达到了30％，3dB圆极化带宽约为26％，同时频带内天线的增益达到4dB。

Design of Miniaturized Circularly-Polarized Microstrip Antenna

A compact broadband circularly-polarized microstrip antenna excited by a probe feed is pro- posed and implemented. The feed network is used to realize dual-fed and attain broad width of circular po- larization. The feed network is designed with the theory of stripline and the miniaturized structure is a- chieved by a U-shaped ground plate. The antenna is of good circular polarization axial ratio, and 26% of 3 dB axial ratio bandwidth, 30% of VSWR≤ 2 impedance bandwidth are obtained. Simulation confirms the measurement results of resonant frequency, The measured gain of antenna is about 4 dB in return loss, axial ratio, bandwidth and radiation pattern work bandwidth.