0.25μm CMOS Dual Feedback Wide-Band UHF Low Noise Amplifier

This paper presents a CMOS low noise amplifier (LNA) for UHF band applications. By using an inverter to enhance the overall transconductance, and a resistive shunt feedback topology with a source degenerated inductor, a wide bandwidth from 50 MHz to 560 MHz is achieved, with a peak power gain of 13.8 dB. A noise figure of 1.8 to 2.4 dB is obtained in the frequency range of 200 MHz and 1.5 GHz. At 450 MHz, this LNA exhibits IIP3 of 6.15 dBm, and input P1dB of -6 dBm. The LNA is biased at 2.4 V, drawing a current of 14 mA. Compared to other published wide-band LNAs, this amplifier achieves the best linearity for NF below 2.5 dB, with low circuit complexity.