A variable gain, 2.5 GHz CMOS low-noise amplifier for mobile wireless communications

A two-stage, variable-gain low-noise amplifier (LNA) which offers good matching and good noise performance is demonstrated. A prototype 2.5 GHz LNA is designed and simulated using 0.13 um RF CMOS process technology. The simulated LNA has a maximum gain of 32.6 dB, input return loss of -44.9 dB, and output return loss of -5 dB. It has a noise figure of 1 dB and input P1dB of -33.9 dBm in high-gain mode, and noise figure of 2.6 dB and input P1dB of -14.6 dBm in low-gain (15.4 dB) mode. The complete device draws 20.3 mA of current from a 1.2 V supply for a total power consumption of 24.4 mW.