Broadband Rectangular Waveguide to GCPW Transition

A broadband transition design between rectangular waveguide and GCPW is proposed and studied. The E-field of GCPW is designed to be gradually changed to that of waveguide via the simple tapered probes and metallic vias. The planar circuit of the transition is fabricated by low cost standard PCB process. The tolerance analysis for this transition is also given. A back-to-back transition prototype at Ka-band is fabricated and measured. The measurement results show that maximum insertion loss of 0.75 dB and return loss of better than 15 dB are obtained within a desired frequency range from 26.5 to 40 GHz. The measurement results agree well with simulation results, which validate the feasibility of this design.