A Broadband Low-Loss 60 GHz Die to Rectangular Waveguide Transition

This letter describes a broadband CPW to standard WR-15 rectangular waveguide transition designed for low-cost PCB technology. This low-loss transition can be be directly integrated to a flip-chipped millimetre-wave integrated circuit. The measured fractional bandwidth of this module is 25%, covering from 52 to 67 GHz. The average measured insertion loss of the transition including a quasi-coax section is 0.5 dB over the 60 GHz band, and the return loss is higher than 15 dB.