二单元圆极化微带天线阵列中介质边缘效应仿真实验分析*

紧凑型双馈圆极化微带天线阵列在E面和H面存在严重互耦,会导致天线阵列的整体性能显著下降.为此,设计了二单元圆极化微带天线阵列,建立了参数化HFSS模型,对天线单元间距、辐射基片切向方向边缘效应对E面和H面互耦影响进行了仿真和分析,结果表明存在临界单元间距值.小于该值时,H面的互耦比E面的严重,反之H面的互耦会随着间距加大而显著下降；对于E面互耦,辐射基片切向方向的介质边缘存在对应最小E面互耦的最佳尺寸,但对于H面互耦,介质边缘效应并不显著.进一步设计了具有典型参数值的实物样品,测试结果验证了上述情况,并表明:介质边缘效应只能改善E面互耦,但对H面互耦的改善需要采用其它方法.

Edge Effect on Mutual Coupling along E and H Planes in Two-element Circularly Polarized Microstrip Antenna Array

There is a severe mutual coupling between any adjacent elements for a compact circularly polarized microstrip antenna array along E-plane and H-plane where each element is fed by two coaxial probes, which will bring remarkable performance reduction to the array. Thus, a two-element circularly polarized microstrip antenna array model is built by HFSS software, in which distance from one patch center to another and patch tangential substrate edge sizes on mutual coupling along E and H planes are simulated and analyzed. The result shows that there is a critical value for the distance. While the distance is less than the critical value, mutual coupling along E-plane is more severe than along the H-plane. Moreover,there is still another critical value for the edge size in the E-plane direction corresponding to a lowest mutual coupling along E-plane. Unfortunately, no optimal value for the edge size in the H-plane direction can bring minimum mutual coupling along the H-plane. At last, one test sample is designed, manufactured and tested, which is almost in consistent with the simulation result.