Broadband transition between waveguide and substrate integrated waveguide based on quasi-Yagi antenna

A novel broadband waveguide-to-substrate integrated waveguide transition is presented. The broadband transition is realised by using an antipodal quasi-Yagi antenna probe inserted into a rectangular metal waveguide. The transition is simulated and measured at 8–18GHz. The measured results show that good agreement with simulation and an insertion loss less than 2.7dB and a return loss better than 10dB are obtained at 9.5–17.5 GHz for a back-to-back structure.