On the analysis of radiation losses in substrate integrated waveguide using mode-matching and method of moments

In this paper we extend a recently published mode-matching and method of moments hybrid technique that efficiently analyzes substrate integrated waveguide (SIW) devices. That method included two fast frequency sweep schemes and already considered the conductor and dielectric losses in the SIW structure. However, it neglected the potential leakage problem due to the periodic gaps. Here a more rigorous analysis is provided so that the radiation losses can be also considered.