位积分方程组矩量法用于精确计算非均匀介质柱的电磁散射

位积分方程组的主要特点是以电磁位为未知函数,这些未知函数在具有不同电磁参数的介质分界面处是连续的,因而在矩量法的实现过程中能够非常方便地应用高阶插值基函数来展开未知函数,以便获得高精度的解。但是,经典的点匹配方案使该模型的数值稳定性较差。本文用位积分方程组矩量法模型计算任意截面非均匀介质柱的电磁散射,采用三角形离散方案和高阶插值基函数,在测试过程中应用新提出的测试方法,克服了原位方程组矩量法模型的数值不稳定性。对矩量法矩阵中自阻抗元素的奇异性处理方法也作了详细介绍。文中提供的数值结果表明,该方法是精确、稳定的。

A MoM Model Based on Potential Integral Equations for Accurately Computing Electromagnetic Scattering by Imhomogenous Dielectric Cylinder

The main characteristic of potential integral equations is that it use electromagnetic potentials as unknowns.Becourse these unknowns are continuous at interfaces between regions of different permittivities and/or permeabilities,high order interpolation basis functions can be easily appllied in the method of moments. But classical point matching scheme is not numerically stable in this discretized model.In this paper,a model using potential integral equations for electromagnetic scattering of penetrable cylinders is proposed.The resulting coupled potential integral equations system is solved by the method of moments in combination with high order interpolation bases in triangle elements and improved matching approach.The new scheme avoids the numerical unstability of the original discretized model.The method for handling the singularity of the self-impedance element in MoM matrix is also presented.The numerical result shows the RCS of 2-D dielectric cylinder can be computed accurately by the proposed method.