Compact monolithic coplanar 94 GHZ front ends

Fully integrated W-band 94 GHz heterodyne receivers in coplanar 0.15 mu m AlGaAs/InGaAs/GaAs PM-HEMT technology are described. The MMICs consist of a multistage low noise RF amplifier, a mixer, and an LO buffer amplifier. Balanced diode and single ended resistive HEMT mixers were investigated. A conversion gain of 13 dB and a DSB noise figure of 6.5 dB were obtained with a very compact 1*4 mm2 front end MMIC, employing cascode amplifiers and balanced rat race diode mixer. The chip size is substantially less than that of any receiver chip published to date.