Analytic Integration Approach for Precise Calculation of MoM Matrix Elements

To solve electromagnetic scattering and radiation problems using the Rao-Wilton-Glisson(RWG) basis function, double surface integrals over triangular domains are computed. When the distance between the source point and the observation point is large, these surface integrals are computed using numerical integration methods that offer high computational accuracy and convenience. However, when the distance between the source point and the observation point is small, the 1/R and 1/R ² components within the surface integral become singular, leading to reduced accuracy when computed using numerical integration alone. Therefore, alternative approaches are required to achieve high computational accuracy when the distance between the source point and the observation point is small. In this paper, we introduce a method for handling singular integrals and provide results from applying this method to example to demonstrate its effectiveness.