65-nm CMOS, W-Band Receivers for Imaging Applications

Two 76-92 GHz receivers, featuring 3-stage cascode LNAs coupled through a transformer to a double-balanced Gilbert-cell mixer and differential DC-5GHz IF buffer, are reported in 65-nm general purpose (GP) CMOS technology. One receiver features a traditional LNA with series-series inductive feedback, while the LNA of the second receiver employs a shunt-series, transformer-feedback cascode stage. Both receivers have a differential down-conversion gain of 12 dB, an input P
_1dB
of -13 dBm, and a double-sideband noise figure of 9-10 dB. They each occupy an area of 550μm×550μm and consume 94 mW. An LO-to-RF isolation of 60 to 59 dB was measured for LO signals in the 80-85 GHz range. The transformer-feedback provides a broader bandwidth input match, lower than -10 dB from 74 to 95 GHz.