A 76-81GHz High-linearity CMOS Receiver Front-end for Automotive Radar

a 76-81 GHz receiver (Rx) front-end is implemented in 65-nm COMS for automotive radar. The front-end consists of a low noise amplifier (LNA), an interstage network with two-stage transformer, and a mixer core with transconductance (G
_m
) stage and quad-switch. Flyback transformer-feedback technique is adopted for the three-stage common source (CS) LNA. Traditional Gilbert-mixer is improved by inset a transformer balun between G
_m
stage and switch stage. Therefore, high-linearity performance can be achieved. The Rx front-end consumes 22mW and the input 1dB compression point (P1dB) is - 15.5 dBm at 80 GHz. The conversion gain (CG) is 8.5-11.5 dB at 76-81 GHz, while noise figure is 7.2-8.7 dB. The chip size is only 0.23 mm2 excluding PADs.