A 18.85 mW 20–29 GHz wideband CMOS LNA with 3.85±0.25 dB NF and 18.1±1.9 dB gain

A 20-29 GHz wideband CMOS low-noise amplifier (LNA) with flat and low noise figure (NF), flat and high gain (S₂₁), and excellent phase linearity property (group-delay-variation is only ±22.6 ps across the whole band) is demonstrated. To achieve flat and low NF, the size, layout and bias of the input transistor were first optimized for minimum NF, and then the inductance of the input inductors was tuned to obtain a slightly under-damped (flat) NF frequency response. In addition, to achieve flat and high S₂₁ and small group-delay-variation, the inductive-peaking technique was adopted in the current-reused stage for bandwidth enhancement. The LNA consumed 18.85 mW power and achieved flat and low NF of 3.85±0.25 dB, and flat and high S₂₁ of 18.1±1.9 dB over the 20-29 GHz band of interest. These are the best NF and S₂₁ performances ever reported for a 21.65-26.65 GHz or a 22-29 GHz wideband CMOS LNA.