Design of wideband waveguide to microstrip transition for 60 GHz frequency band

In this paper, design of a planar wideband waveguide to microstrip transition for the 60 GHz frequency band is presented. The designed transition is fabricated using standard high frequency multilayer printed circuit board technology RO4003C. The waveguide to microstrip transition provides low production cost and allows for simple integration of the WR-15 rectangular waveguide without any modifications in the waveguide structure. Results of electromagnetic simulation and experimental investigation of the designed waveguide to microstrip transition are presented. The transmission bandwidth of the transition is equal to the full bandwidth of the WR-15 waveguide (50-75 GHz) for the -3 dB level of the insertion loss that was achieved by special modifications in the general aperture coupled transition structure. The transition loss is lower than 1 dB at the central frequency of 60 GHz.