A 40/85 GHz dual-band, bidirectional variable gain amplifier

A dual-band, bidirectional amplifier is proposed for millimeter-wave front-ends in CMOS silicon-on-insulator (SOI). The circuit is electronically controlled to amplify in either the forward or reverse direction at either 40 GHz (Q-band) or 81 GHz (W-band). The measured amplifier has a gain variation of 20 dB with a peak gain of 4.6 dB at both 40 GHz and 81 GHz. The circuit is fabricated in a 45-nm CMOS SOI process with an active area occupying only 0.17 mm
²
of die space.