A 77-GHz active millimeter-wave reflector for FMCW radar

An 18-mW active millimeter-wave reflector fabricated in 45-nm SOI CMOS technology exhibits a peak gain of 20 dB at 77 GHz, a 3-dB bandwidth of 5 GHz from 75.5 to 80.5 GHz, and a 50-Ω noise figure of 7.5-8.5 dB over the same frequency band. It consists of an LNA, a BPSK modulator and two variable gain output stages each driving a separate transmit antenna. The chip occupies 570μm×880μm and is flip-chip mounted on a 7mm×7mm flexible interposer with two transmit and one receive antenna.