A CMOS 2-11 GHz Continuous Variable Gain UWB LNA

In this paper, a new CMOS variable gain low noise amplifier (VG LNA) with continuous gain variation for 2-11 GHz employing a resistance feedback current reuse stage and a cascode stage is presented. By controlling the transimpedance feedback resistor of the first stage and the bias current of the second stage, a continuous gain tuning range of 26 dB is achieved without influencing the input match and output match. The VG LNA is simulated based on the TSMC 0.18 mu m CMOS process and shows the following performance at the highest gain mode: S11 is less than -10 dB from 3 to 10.2 GHz, and S22 is less than -18 dB from 2 to 11 GHz. In the total 2-11 GHz frequency range, the gain is more than 17 dB, and the noise figure is less than 3.8 dB, while drawing 7.57 mA from 1.4 V supply voltage.