口径耦合微带天线互耦时域有限差分法分析

FDTD Analysis of Mutual Coupling in Aperture-coupled Microstrip Antennas

在阵列天线中,互耦是阵列性能下降的一个重要因素,对互耦进行正确的评估、计算,有助于深入了解阵列特性并指导设计工作。采用时域有限差分法计算了口径耦合微带天线互耦系数,天线建模中引入非均匀网格和电阻性电压源,微带线与馈源用阶梯过渡来连接,在保证计算精度的前提下,计算空间和计算机时间大大减少,计算结果与矩量法及测量结果基本一致。

In an antenna array, mutual coupling is a significant reason of performance degradation, thus an accurate evaluation of mutual coupling will be helpful to the designing work and the comprehension of the performance of antenna arrays. The mutual coupling of microstrip antenna arrays was calculated by the finite - difference time - domain （FDTD） method. Nonuniform mesh and a voltage source with a lumped resistance type internal impedance were used in the model. The stair - stepped transition from the source to the microstrip line was used to provide a relatively smooth connection from the single electric feed location to the microstrip. The space of calculations and computer time are sharply reduced, but the numerical precision is not declined. The results of the simulation are found to be in close agreement with those derived by using the method of moments （MOM） and actual measurements.