Efficient generation of method of moments matrices using the characteristic function method

We present a new, fast, and efficient technique for computing the MoM matrix elements from Rao-Wilton-Glisson (RWG) bases, one that does not require evaluating the usual surface integrals involving the expansion and testing functions. The matrix elements are represented in terms of characteristic functions (CFs), which can be expressed in a closed canonical form. These universal CFs make matrix generation more efficient and faster than the conventional triangular facet interaction scheme. The proposed technique can be applied for any subsectional basis functions other the RWG if the size of the basis function is small enough compared to the wavelength and the distance between the source and the testing basis functions is beyond a nominal distance. The proposed approach is validated for several canonical geometries, and the accuracy of the generated matrix elements, as well as the radar cross-section (RCS) has been verified.