A Tri (K/Ka/V)-Band Monolithic CMOS Low Noise Amplifier with Shared Signal Path and Variable Gains

This paper presents a single-signal-path tri-band (K/Ka/V) variable-gain low noise amplifier (LNA) fabricated in 28-nm bulk CMOS technology. This LNA uses a common gate input stage with a Triple-Coupling Transformer (TCT) to achieve better impedance matching across three desired bands than those of prior arts and enable the necessary gm-boosting to suppress undesired noise.This LNA consists of six stages and offers variable power gains from -5.5 to 29.5 dB (24 GHz), -5.5 to 32.4 dB (33 GHz), and -11.5 to 22.2 dB (50 GHz) with respective minimum noise figures of 5.63 dB, 4.55 dB, and 5.96 dB. Its 3 dB bandwidths (BW3dB) are measured as 3.4 GHz (K-band), 3 GHz (Ka-band), and 14.8 GHz (V-band), respectively. This LNA consumes 25.6 mW from a 1-V supply and occupies 0.22 mm2 without pads in silicon real estate.