Compound field integral equation approach for analyzing quasi-waveguide structures

In this article, a compound field integral equation approach has been applied to analyze the problem of quasi-waveguide structures, that is, structures consisting of a main waveguide with a constant cross section that may bear an arbitrary number of printed circuits backed by dielectric substrates. A detailed mathematical procedure is described to retrieve modal scattering parameters conventionally defined in planar multilayered structures excited by wave ports. In the case that the structure as well as the excitation holds symmetry requirements, simplifications may be applied to considerably improve the usage of computational resources. Formulations providing the theoretical background for applying symmetry conditions have also been developed in the context of this work.