A 12–40 GHz low phase variation highly linear BiCMOS variable gain amplifier

An ultra-wideband low phase variation variable gain amplifier (VGA) in 0.18/am BiCMOS process with high linearity is presented in this paper. The proposed VGA uses novel current steering gain blocks to achieve gain steps with low phase variation. The VGA has a measured gain range of 6.3-8.1 dB over the entire frequency range of 12-40 GHz and shows a phase variation of 0.2-0.78 °/dB. The VGA achieves a simulated input P1dB of 0 dBm at 26 GHz while consuming only 20.5 mW from 1.5 V power supply and occupies an active area of just 0.05 mm². The VGA shows 7.6 times better Figure of Merit as compared to current state-of-the-art VGAs.