A 77.3-GHz 3.36-dB NF LNA with Cross-Coupled Noise Cancellation and Low-Loss Input Matching Transformer in 22-nm CMOS

This paper presents a 77-GHz low-noise amplifier (LNA) for automotive radar. The proposed front-end employs a hybrid common-source/common-gate (CS/CG) first stage with cross-coupled noise cancellation (CC-NC), achieving low input impedance (Zin), intrinsic noise suppression, and enhanced effective transconductance (Gm). The reduced input impedance enables a 1:1 transformer (XFMR)-based input matching network (IMN), which provides a higher coupling coefficient and quality factor than conventional 1:2 implementations, mitigating insertion loss (IL). The subsequent stages employ neutralization and inductive degeneration to realize simultaneous noise and power matching while maintaining high gain and robust stability. Fabricated in 22-nm bulk CMOS, the prototype achieves a peak gain of 26.2 dB at 77.3GHz with a 4.6-GHz bandwidth. It attains a minimum measured noise figure (NF) of 3.36 dB at 76 GHz while consuming 18.6mW from a 0.9-V supply, demonstrating state-of-the-art noise performance among bulk-CMOS millimeter-wave LNAs.