A fast integral equation technique for shielded planar circuits defined on nonuniform meshes

In this work, the groundwork is laid out for the realization of efficient integral-equation/moment-method techniques, with arbitrary types of basis functions, for the computer-aided design (CAD) of geometrically complex packaged microwave and millimeter-wave integrated circuits (MMIC´s). The proposed methodology is based on an accelerated evaluation of the Green´s functions in a shielded rectangular cavity. Since the acceleration procedure is introduced at the Green´s function level, it becomes possible to construct efficient shielded moment method techniques with arbitrary types of basis-functions. As an example, a Method of Moments (MoM) is implemented based on the mixed potential integral equation formulation with a rectangular, but nonuniform and nonfixed, mesh. The entire procedure can be extended to multilayer substrates