基于MEMS技术的共面耦合式圆极化微带天线的设计与仿真

Design and Simulation of MEMS-Based Circularly Polarized Microstrip Antenna with Coplanar Coupling

研究了一种工作在Ka波段,基于MEMS微加工工艺的圆极化微带天线。采用微带馈线与贴片辐射单元非接触、共面临近耦合的馈电方式,可以在不改变贴片与馈线本身的尺寸且无需额外增加匹配网络的情况下调节阻抗匹配,有效地提高了馈线与辐射元的阻抗匹配度与可调性,简化了天线结构。使用3dB电桥移相器实现圆极化,结构规范,圆极化效果好。使用有限元仿真软件AnsoftHFSS对其进行了仿真优化,得出了一组较优参数,此时天线中心频率为35GHz,增益为6.86dB,驻波比≤2时阻抗带宽为4GHz(约11.4%),轴比<3dB时带宽约为5.9GHz(约16.9%)。

A circularly polarized microstrip antenna based on MEMS （ Micro-Electro-Mechanical Systems） micro-fabrication technology is discussed. The antenna is fed by a microstrip through coplanar coupling. The radiation efficiency and impedance matching are improved, while the coupling efficiency is not affected. Ansoft HFSS, a high frequency structure simulation software based on finite element method （ FEM）, is used to analyze the antenna performances. A set of optimized parameters is given after simulating different parameters and comparing and analyzing the simulation results, such as SI 1 and gain of the antenna. The antenna works at the center frequency of 3 5 GHz , the bandwidth is 4 GHz with VSWR ≤ 2 , and 5A 9GHz with AR≤3dB. and the gain is 6.86dB.