Charge Recovery for the RWG-Based Method of Moments

This letter is concerned with methods of obtaining a better approximation to the true surface charge density on a structure by post-processing the surface divergence of an RWG-based method-of-moments (MoM) solution current. It is shown that derivative recovery techniques developed for the finite element method (FEM) are not suitable. A simple and inexpensive recovery technique based on the properties of RWG basis functions is introduced for charge recovery in the MoM. Satisfactory performance of the proposed method is demonstrated, and its application to a posteriori error estimation is shown.