Stabilized Macro Basis Function MoM for Wideband Analysis of Wire Coupling

Journal article, 2026

This article presents a macro basis function (MBF) set to represent wire surface currents in the method of moments (MoM), for full-wave computational electromagnetic modeling of complex wire coupling effects over broad frequency ranges. Such modeling is important for design and operational characterization of systems relying on wires for data and power transmission, where it is necessary to ensure that electromagnetic interference is acceptably low to maintain electromagnetic compatibility. The MBFs allow for both axial and circumferential components and variations. They are constructed from standard MoM basis functions for representing surface current density on triangle element meshes, resulting in significantly fewer unknowns. The MBFs build on a previously proposed set. They are reformulated to ensure that solenoidal current flow can be exactly represented, thereby eradicating the occurrence of spurious solutions. This enables stable, accurate, and efficient wideband analysis, as demonstrated with crosstalk and radiated immunity results for various transmission line coupling test cases. For these applications, it is found that existing methods tailored to wire coupling analysis, namely, thin-wire MoM and hybrid transmission line theory solvers, are generally not reliable.