Packaging of MMIC by using gap waveguide and design of a microstrip to ridge gap waveguide transition

In this work, gap waveguide based packaging technique is used to improve the isolation among critical microwave circuit components such as high gain amplifier chain. Amplifier chains at Ka-band were tested for a stable forward gain and it was found that-with gap waveguide packaging, 65~70dB of forward gain is achievable without the problem of self-resonance. Apart from the new packaging technique, a low-loss transition from microstrip to ridge-gap waveguide had been designed and tested. This transition is a key component to connect such amplifier chains to a planar slot array antenna. Experimental results for manufactured back to back transition show 14 dB return loss over 55% relative bandwidth from 2343GHz.