A full wave space domain analysis technique of open microstrip planar circuits

The authors present a full wave space domain technique for the analysis of open microstrip planar circuits. The approach starts from an electric field integral equation (EFIE) for the surface current which is solved by the method of moments. The current is expanded in bilinear basis functions in the nonboundary cells of the grid and in special functions in the edge and corner cells. The latter functions take the well-known square root edge behavior into account. This results in very accurate current modeling. The excitations are the fundamental modes propagating on the port transmission lines. The integral equation is tested with pulse functions. The elements of the interaction matrix are calculated in the spatial domain. A Green's Dyadic database oriented approach makes the technique very efficient. Attention is focused on the calculation of the cell-cell coupling elements of the interaction matrix. Simulated results for a single stub circuit are compared with simulated and experimental data from the literature.<>