2.5 dB NF 3.1-10.6 GHz CMOS UWB LNA with small group-delay variation

A 3.1-10.6 GHz ultra-wideband low-noise amplifier (UWB LNA) with excellent phase linearity property (group-delay variation is only +/- 16.7 ps across the whole band) using standard 0.13 mu m CMOS technology is reported. To achieve high and flat gain and small group-delay variation at the same time, the inductive peaking technique is adopted in the output stage for bandwidth enhancement. The UWB LNA achieved input return loss (S I,) of -17.5 to -33.6 dB, output return loss (S-22) of -14.4 to -16.3 dB, flat forward gain (S-21) of 7.92 +/- 0.23 dB, and reverse isolation (S-12) of -25.8 to -41.9 dB over the 3.1-10.6 GHz band of interest. A state-of-the-art noise figure (NF) of 2.5 dB was achieved at 10.5 GHz.