A K-/Ka-band LNA With 3.5 ±0.15 dB Noise Figure Using Triple-Coupled Transformer Matching Network in 65-nm CMOS

This work presents a 5G millimeter-wave low-noise amplifier (LNA) featuring a transformer-based triple-coupled matching network architecture, exhibiting a wideband input matching and optimized noise performance. Implemented in 65-nm CMOS technology, the proposed LNA achieves a peak gain of 20.5 dB with a 3-dB bandwidth from 21 to 38 GHz. The design demonstrates excellent noise characteristics with a flat noise figure of 3.5 dB and minimal variation within ±0.15 dB across the entire band. The simulated S11 is less than −15 dB across most of the frequency band. By incorporating current-reuse topology, the circuit maintains a power consumption of 17.26 mW while occupying a core area of 0.175 mm².