Utilization of mode-match technique for calculating the dispersion characteristic of 2D periodic structure

In this work the Mode-Matching-Point-Matching (MM-PM) has been applied to determine the dispersion characteristics for a two-dimensional (2-D) structure. The 2-D structure is defined as a structure with a homogeneous dielectric substrate backed by a ground-plane on one side and an array of strip lines on the other. In this case, a strip line is assumed to have an infinitesimal small thickness. The developed MM-PM technique uses two well documented methods: the mode- matching and point matching technique to solve for both the transverse electric (TE) and the transverse magnetic (TM) modes at an interface. The two methods together produce a set of equations which are expressed in a homogenous matrix form. Using singular value decomposition, the homogenous matrix is solved to produce the dispersive characteristics of the microstrip. The generated numerical results for both the one-dimensional (1-D) and 2-D structures are compared to Ansoft Designer and Ansoft HFSS simulated results. Also experimental results from fabricated structures are compared to theoretical results. A good match is obtained from all the different results. Overall the results are in general very good agreement. These results demonstrate that the MM-PM technique, characterized by its simplicity, can be used as a possible alternative method for the determination of dispersion characteristics of structure