3.1 dB NF 20–29 GHz CMOS UWB LNA using a T-match input network

Abstract

A 20–29 GHz CMOS ultra-wideband (UWB) low-noise amplifier (LNA) with excellent input return loss (S11), flat and high power gain (S21), and flat and low noise figure (NF) is demonstrated. Wideband input impedance matching was achieved by using the proposed T-match input network to generate two S11 dips. Flat and high S21 was achieved because the inductive-peaking second stage and the current-reused final two stages can compensate the gain degradation of the source-degenerative first stage at medium and high frequencies, respectively. Flat and low NF was achieved by adopting a slightly under-damped Q-factor for the second-order NF frequency response. The LNA consumed 22.07 mW and achieved S11 of −15.5 to −26.8 dB, S21 of 16.2±2.5 dB, minimum NF (NFmin) of 3.1 dB (at 20 GHz), and an average NF of 3.6 dB over the 20–29 GHz band of interest, one of the best reported average NF performances for a 24 GHz band CMOS LNA with bandwidth wider than 6 GHz in the literature.