Design of Hollow Waveguide to Substrate Integrated Waveguide Transition in Multi-layer Substrate

Abstract

Substrate Integrated Waveguide (SIW) is a low loss transmission line which can be used to connect an antenna to a backed RF circuit in the millimeter wave band. A multi-layer substrate is effective to integrate RF circuits and antennas. Therefore, a transition between a hollow waveguide and a SIW in multi-layer substrate is necessary. However, reflection loss generates at the connections between the hollow waveguide and the SIW in each layer. In this study, a back short and window structures are proposed to use for matching circuit in the transition. Transitions from hollow waveguide to SIWs in multilayer substrate were designed for low loss over wide bandwidth.