A Simple Strip Model in the Volume-Surface Integral Equation for Analysis of Arbitrary Probe-Fed Conformal Microstrip Antennas

A strip model is incorporated in the volume-surface integral equation (VSIE) to simplify the analysis of the probe-fed conformal microstrip antennas (CMSAs) with arbitrary shapes. The thin wire-surface junction of the feeding probe and the patch is transferred to the surface-surface junction that can be modeled by using Rao-Wilton-Glisson (RWG) basis functions easily. Thus, the use of complicated attachment mode basis function in the conventional VSIE is eliminated, which simplifies the calculation of the method-of-moments (MoM) matrix. The construction of RWG basis functions at the surface-surface junction is detailed as well. An effective remedy is also proposed to overcome the computation breakdown in the near-singularity treatment when the field point locates at the extension of one side of the source domain. Numerical results show the reliability and accuracy of the proposed method.