Two CMOS Dual-Feedback Common-Gate Low-Noise Amplifiers With Wideband Input and Noise Matching

This paper presents two CMOS common-gate (CG) low-noise amplifiers (LNAs) using different dual-feedback techniques, significantly reducing noise figure (NF) to around 2 dB over a wide frequency range. The proposed first CG LNA uses gm-boosted feedback and shunt-series transformer feedback to relieve the tradeoff between input and noise matching. The proposed second CG LNA further extends the input matching bandwidth by using gm-boosted feedback and shunt-shunt transformer feedback. Moreover, the transformer used for feedback in both CG LNAs causes gain peaking and thus a considerable increase of 3-dB gain bandwidth. After implementation in a 0.18- μm CMOS process, the first and second CG LNAs achieve an NF of 1.9-2.6 dB over a 3-dB gain bandwidth of 7 and 10 GHz, respectively. The comparison between simulated and measured results shows a good agreement.