Rigorous losses evaluation in the numerical analysis of SIW structures

This paper presents a study of the effect of losses in slotted substrate-integrated-waveguides by means of a rigorous numerical approach consisting in a mode matching coupled with a method of moments. Losses can be due to the conducting plates shielding the structure and to dielectrics inside the waveguide (both in the substrate and in dielectric posts). The first effect is modeled through an effective impedance condition on each plate, while the second is described by complex-valued permittivities.