Design and performance of a W-band microstrip rat-race balanced mixer

Abstract

The design and measured characteristics of a W-band microstrip rat-race balanced mixer are presented in this paper. The single balanced mixer is realized by using a configuration of a rat-race hybrid-ring with five ports and two DMK2790 GaAs Schottky diodes. The radio frequency (RF) signal and local oscillator (LO) signal pass through the antipodal finline waveguide-to-microstrip transitions to the microstrip circuit. In order to verify the design, the mixer is fabricated on 0.127 mm thick Duroid RT 5880 substrate. Measurement result shows its conversion loss is less than 13.5 dB from 90 GHz to 97 GHz.