Full-band transition from substrate integrated waveguide to rectangular waveguide

A novel substrate integrated waveguide to rectangular waveguide (RWG) transition for effective power transfer is proposed. The substrate taper is inserted into a conventional height-stepped impedance transformer of the RWG region to improve transmission loss and bandwidth. The transition is designed to cover the entire K-band (18-26 GHz), showing a return loss of 20 dB. A back-to-back transition has been fabricated to verify the proposed transition. The experimental results show good agreement with the analysis. The transmission loss of the stand-alone transition is 0.22 dB at 21.7 GHz with a usable bandwidth of 36%.