Broadband air-filled SIW to waveguide transition for interconnect, instrumentation and measurement applications

This paper presents a broadband transition from a standard waveguide to an air-filled substrate integrate waveguide (AFSIW). The proposed transition can be used to interconnect low-cost and high performance AFSIW based microwave and millimeter-wave substrate integrated circuits with waveguide systems. For instrumentation and measurement purposes, a test-fixture based on the reported transition is introduced. A back to back experimental validation of the transition in the 16 to 22 GHz frequency range, shows a return loss of better than −25 dB and an insertion loss of 0.12 ±0.05 dB (0.06 ±0.05 dB per transition).