Overall Formulation for Multilayer SIW Circuits Based on Addition Theorems and the Generalized Scattering Matrix

This letter presents a multilayer formulation for substrate integrated waveguide circuits, based on the analytical connection of cylindrical modes of sections described by their generalized scattering matrix (GSM). Sections containing arbitrary elements, defined by feeding and cylindrical ports, are analyzed using the finite element method with fast frequency sweep to obtain their GSM.