A high linearity variable gain LNA for WCDMA receiver front-end

A high linearity variable gain low noise amplifier (VGLNA) used for WCDMA receiver is presented. Power constrained simultaneous noise and input matching (PCSNIM) technique is adopted to design the inductive source degenerated LNA. To improve the dynamic range of the receiver, capacitive divider and current steering technique are adopted to implement the three gain modes. The chip was manufactured using SMIC 0.13-μm CMOS technology. The resulting VGLNA achieves 2.65 dB noise figure with 15.9 dB voltage gain, and 2.3 dBm IIP3 at high gain mode. The core fully differential VGLNA consumes 8 mA from a 1.5 V power supply.