Equivalent circuit model of coaxial probes for patch antennas

Abstract

An equivalent circuit model of coaxial probes is derived directly from the intrinsic via circuit model. As all the higher-order evanescent modes have been included analytically in the parasitic circuit elements, only the propagating mode needs to be considered by the simplest uniform-current model of a coaxial probe in numerical solvers such as -nite element method (FEM) or -nite di®erence time domain (FDTD). This avoid dense meshes or sub-gridding techniques and greatly reduces the computational e®orts for accurate calculation of the probe input impedance. The derived equivalent circuit model and the new feeding technique have been validated by both analytical formulas and numerical simulations.