Physics-Based Via and Waveguide Models for Efficient SIW Simulations in Multilayer Substrates

In this paper, the conventional physics-based via (PBV) model is extended to multilayer substrate integrated waveguide (SIW) structures with via feeds. Furthermore, a novel PBV model for a more efficient modeling of multilayer SIW is proposed. This novel method allows to describe SIWs as transmission lines and to model the coupling between the layers with an equivalent circuit near-field model. Both PBV models are compatible and can be combined within a framework for modeling complex multilayer SIWs in an efficient manner. Results obtained by both methods are compared with full-wave solver results and show very good agreement from below cutoff frequency to about three times the cutoff frequency as well as a speed up of several orders of magnitude.