Recent enhancement in the analysis of wire-surface structures with the Method of Moments

This paper provides an in-depth analysis of the use of junction basis functions as applied in the Method of Moments (MoM) to properly discretize the junction between wires and surfaces. We first present a simple and efficient numerical procedure, based on the singularity cancellation scheme, for evaluating singular and near-singular potential integrals involving junction basis functions. Then, to avoid severe poor conditioning of the MoM matrix at very low frequencies, we describe the generation of solenoidal bases on bodies composed of arbitrarily shaped surfaces connected to wires. Finally, we extend the quasi-Helmholtz representation of the unknown current to a hierarchical scheme that results in a physics-based preconditioner for geometrically complex and/or finely meshed structures, and/or low frequency problems. The performance of the proposed basis decomposition and representation is confirmed by the reported numerical examples.