Design of Ultra-Wideband Low Noise Amplifier with Excellent Port Matching and Gain Flatness

A design method of ultra-wideband three-stage Low Noise Amplifier (LNA) using 65nm CMOS technology is presented in this paper. Gm-boost technique is used to suppress the drain noise of the common-gate (CG) transistor in the first-stage. The gain peaking frequency of each stage's amplifier is suitably adjusted to realize excellent gain flatness. Inductive feed-forward technique is introduced to achieve broadband input matching and to make the layout more compact. In the post simulation, the proposed LNA achieves 3.7-5.7dB Noise Figure (NF) across 12.7GHz to 49.8GHz bandwidth, with Sll<-10dB, S22<-14dB, and S21=11.0-12.7dB. The LNA consumes 25.7mW dc power, and occupies 0.27mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> core area.