A fully integrated LNA for 3-5 GHz UWB wireless applications in 0.18-μm CMOS technology

In this paper, a fully integrated low noise amplifier (LNA) employing a cascode topology and an RC feedback network is proposed for an ultra-wideband (UWB) wireless system in a 0.18-mum RF CMOS technology. By using two single-stage cascode topologies, the function of both a single-end input and differential output is achieved. The wideband input impedance and noise matching is conducted by employing an RC feedback network, a degenerating inductor (L_s) and a gate one (L_g). The simulation results show that the average power gain (S₂₁ or S₃₁) is about 11 dB and the input return loss (S₁₁) is less than -10 dB over the whole frequency range of 3 to 5 GHz. In addition, the noise figure (NF) is from 2.5 to 3.5 dB over 3-5 GHz while consuming 49 mW under a 1.8 V single supply voltage.