Two Dimensional Multi-Port Method for Analysis of Propagation Characteristics of Substrate Integrated Waveguide

In this paper, two dimensional multi-port method is used to analyze substrate integrated waveguide by using Green's function approach to obtain the impedance matrix of equivalent planar structure. Modes propagation constant of substrate integrated waveguide, as a periodic structure, is calculated by applying Floquet's theorem on the impedance matrix of a unit cell. Field distribution of the propagating mode is obtained by this method. Results obtained by this method are verified, in a broad range of dimensions, by comparing with published results and also those calculated by commercial electromagnetic simulator, HFSS. Electromagnetic band gaps and mode conversion phenomenon as properties of periodic structures are also observed and investigated. Mode conversion in SIW is reported for the first time by our proposed method.