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 (iCP1 dB) of -16.0 dBm and a minimum gain of 1.6 dB within iCP1 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