Efficient CAD of boxed microwave circuits based on arbitrary rectangular elements

In this paper, we describe a very accurate and computationally efficient co mputer-aided design (CAD) tool for the analysis and design of a wide class of boxed microwave circuits composed of arbitrary rectangular elements prin ted on dielectric layers. The theoretical derivations are based on an integ ral equation formulation, and call for the evaluation of the boxed multilay er Green's functions, thus leading to a tool that is valid for an arbitrary number of circuits and dielectric layers. In addition to theory, compariso ns with measured results are presented, and several practical filter struct ures are also investigated, thus clearly demonstrating that the CAD tool de veloped can indeed be used very effectively for the design of a large varie ty of microwave circuits.