A L-band gain controllable CMOS LNA

A L-band gain controllable LNA with digital programmable gain controlling method is presented in this paper. A simple gain control circuit is exploited and added in the second stage of a cascade LNA to achieve gain tuning. Shunt-resistor feedback and noise cancelling technique are introduced in the first stage for excellent input match and low noise performance. Fabricated with 0.13-¿m RF CMOS process, the LNA die area with pads is 0.9×0.7mm
²
. Measured results show that maximum power gain and minimum noise figure are 19.6dB and 2.6dB respectively. The LNA has four gain modes in all, tuned by three-bit digital programmed signal with a tuning range of 8dB about 2.5dB/step. Power consumption of the LNA is 14.4mW and typical IIP3 at 1.2GHz is -8dBm.