RWG Basis Functions for Accurate Modeling of Substrate Integrated Waveguide Slot-Based Antennas

In this article, we propose the implementation of a triangular mesh along with Rao-Wilton-Glisson (RWG) basis functions to improve the performance and flexibility of a mixed mode-matching (MM)/method-of-moments (MoM) algorithm dedicated to substrate integrated waveguide (SIW) antennas analysis and optimization. These basis functions represent equivalent magnetic currents on either coupling or radiating apertures. In the initial implementation, the entire domain sine basis function was presented, providing fast and accurate simulations for electrically thin rectangular slots. In order to treat wider slots and other geometries, we add here RWG functions, present the theoretical framework of this approach, and highlight its potential through concrete examples.