A 1-V 5 GHz Variable Gain Low Noise Amplifier in 0.18-μm CMOS

This paper describes a 1-V 5 GHz fully differential variable gain low noise amplifier (VGLNA) in a 0.18-mum CMOS process. The LNA provides 50-Omega input impedance and utilizes a tuned load to provide high selectivity. The VGLNA achieves a maximum small signal gain of 10.11 dB within 1-dB compression point (iCP_{1 dB}) of -16.0 dBm and a minimum gain of 1.6 dB within iCP_{1 dB} of -14.5 dBm. In the high gain and low gain modes, the noise figures (NFs) are 1.94 dB and 3.96 dB, respectively with good input return loss. The LNA´s IIP3 in the high gain mode is -5.15 dBm. The LNA consumes only 6.4 mA of current from a 1-V power supply