A Passive W-Band Imaging Receiver in 65-nm Bulk CMOS

A passive imaging receiver operating in the W-band around 90 GHz has been realized in a digital 65-nm CMOS process. The circuit, occupying only 0.41 mm2, integrates an SPDT switch with 4.2 dB loss and 25 dB isolation, a five-stage telescopic cascode LNA with 27 dB gain at 90 GHz, and a W-band square-law detector, all consuming less than 33 mA from 1.2 V. A version of the receiver without the input SPDT switch has a peak responsivity of over 200 kV/W and a minimum NEP of less than 0.1 pW/ Hz. The full Dicke radiometer, which includes the input switch, achieves a responsivity of 90 kV/W and an NEP of 0.2 pW/ Hz. This work represents the first W-band passive imaging receiver to be implemented in standard CMOS with this level of integration.