FSS电磁散射方向特性的快速计算

基于渐近波形估计(AWE)技术和矩量法(MOM)快速获取了一维频率选择表面(FSS)的电磁散射方向特性.首先采用MOM法将FSS的电场积分方程(EFIE)转化为矩阵方程,并确定角度导数矩阵方程(MEFD);再在某一给定角度处求解MEFD,得到给定角度处的各阶角度导数感应电流;最后根据Pade逼近理论由给定角度处的角度导数感应电流确定FSS在任意角度入射波照射下的感应电流.根据感应电流及谱域Floquet谐波模计算FSS的电磁散射方向特性.计算结果表明,AWE完全能逼近MOM逐点扫描计算的结果,同时在计算速度上可加快二十多倍.

Fast Calculation of the Electromagnetic Scattering Directional Characteristics of Frequency Selective Surfaces

The method of moments (MOM) in conjunction with the asymptotic waveform evaluation (AWE) technique is applied to calculate the electromagnetic scattering directional characteristics of one-dimensional frequency selective surfaces (FSS). The electric field integral equation (EFIE) of FSS irradiated by the electromagnetic (EM) wave is firstly changed into the matrix equations of the induced currents using MOM, and the matrix equations of an angular derivative (MEAD) can be then obtained from the matrix equations. In the AWE technique, the induced currents of angular derivative at a given angle within an angular are first obtained to find MEAD. The induced currents at any angle within the angle can be then obtained from the induced currents of an angular derivative at given angle via the Pade approximation. According to the induced currents and the Floquet harmonic of the spectral domain, the EM scattering directional characteristics can be calculated. It was observed that the results of AWE can exactly approximate those of MOM that sweeps frequency at a certain interval, and AWE technique can result in considerable CPU time saving.