Analysis and Design of a Reconfigurable Multimode Low-Noise Amplifier Utilizing a Multitap Transformer
A 2.4-5.4-GHz CMOS reconfigurable low-noise amplifier (LNA) is designed. It consists of two stages: a broadband input stage for a steady input matching and noise performance, and a reconfigurable band-selective stage which provides a wide-range frequency tuning from 2.4 to 5.4 GHz and a 12-dB stepped gain with linearity adjustment. The frequency tuning is conducted by a multitapped switching inductor and varactors. Careful design of the switching inductor achieves consistent performance among frequency configurations. The stepped gain and linearity adjustment are provided by a size-switchable transistor with a variable biasing. Fabricated in 0.13 mum CMOS technology this LNA exhibits performance including up to 25 dB power gain, 2.2-3.1 dB noise figure and less than 5 mW power consumption under 1 V power supply.