60 Ghz Receiver Front-End with Wideband Microstrip-To-Waveguide Transitions

Abstract

A new 60GHz receiver front-end is presented in this paper. The front-end consists of a sub-harmonic down-converter module and an amplifier module, which are connected through a pair of microstrip-to-waveguide transitions. Both transition structures consist of a quarter-wavelength short-circuited waveguide, an openended waveguide, and a microstrip probe printed on a Rogers 5880 thin film substrate. An extended ground has been applied to change the EM field in the waveguide to achieve a better coupling. Simulated and measured results show that the total insertion loss is below 0.6 dB, and the return loss is better than −15 dB from 58 GHz to 65 GHz. The proposed transitions are integrated into the receiver front-end, which can provide a 15 dB conversion gain over the 7 GHz bandwidth. The performance of low loss, wide bandwidth and simplicity for fabrication makes it suitable for 60 GHz frontend integration.