A Compact 0.2-1.6 GHz 20 MHz-Bandwidth Passive-LNA Exploiting an N-Path 1:3 Transformer

A compact passive low-noise amplifier (pLNA) with an N-path 1:3 transformer is demonstrated. Consisting of only switches and capacitors, the N-path 1:3 transformer offers passive voltage gain and high-Q bandpass filtering in a smaller area than the step-up spiral transformer. The proposed 4-path 20 MHz-bandwidth pLNA realized in 55-nm CMOS occupies only a 0.09-mm2 active area and consumes 0.7-3.1 mW between 0.2 GHz to 1.6 GHz. The post-layout simulations show that the proposed pLNA achieves a 6.2-8.8-dB passive voltage gain, 2.31-3.68-dB noise figure (NF), 5.04-14.17-dBm in-band (IB) input-referred third-order intercept point (IIP3), and 24.52-27.16-dBm out-of-band (OOB) IIP3 at an 80-MHz offset.