A 2 dB NF, fully differential, variable gain, 900 MHz CMOS LNA

Abstract

A fully differential 900 MHz CMOS LNA using, as input stage, nMOS and pMOS inductively degenerated pairs, in shunt configuration, achieves the following performance: 2 dB NF, 22 dB voltage gain, -3 dBm IIP3 with 8 mA current consumption. As additional feature of this LNA is a variable gain. Measurements have been performed on packaged dies. No external components are used, except for an SMD inductor (used for tuning purposes), placed in series with the on-chip gate spiral inductor.