Wideband common-gate CMOS LNA employing dual negative feedback with simultaneous noise, gain, and bandwidth optimization

This paper presents a wideband common-gate (CG) LNA architecture that overcomes the fundamental tradeoff between power and noise match without compromising its stability. The proposed architecture can achieve the minimum noise figure (NF) over the previously reported feedback amplifiers in a CG configuration. The proposed architecture achieves broadband impedance matching, low noise, large gain, enhanced linearity, and wide bandwidth concurrently by employing an efficient and reliable dual negative-feedback. An amplifier prototype was realized in 0.18-μm CMOS, operates from 1.05 to 3.05 GHz, and dissipates 12.6 mW from 1.8-V supply while occupying a 0.073-mm² active area. The LNA provides 16.9-dB maximum voltage gain, 2.57-dB minimum NF, better than -10-dB input matching, and -0.7-dBm minimum IIP₃ across the entire bandwidth.