Substrate Integrated Waveguide couplers: A semi-analytical design approach based on side leakage

Substrate Integrated Waveguide, an emerging technology for microwave and mm-wave circuits, can be used to manufacture several different devices, in particular couplers. A straightforward implementation for SIW couplers is based on a narrow-wall multi-hole architecture. This paper presents a semi-analytical approach, based on the quantitative determination of the SIW side leakage, to design this type of SIW couplers with arbitrary coupling. The proposed approach is verified against full-wave simulations.