A new wideband LNA using a gm-boosting technique

Abstract

A new broadband low-noise amplifier (LNA) is proposed. The conventional common gate (CG) LNA exhibits a relatively high noise figure, so active gm-boosting technology is utilized to restrain the noise generated by the input transistors and reduce the noise figure. Theory, simulation and measurement are shown. An implemented prototype using 0.13 μm CMOS technology is evaluated using on-wafer probing. S11 and S22 are below −10 dB across 0.1–5 GHz. Measurements also show a gain of 18.3 dB with a 3 dB bandwidth from 100 MHz to 2.1 GHz and an IIP3 of −7 dBm at 2 GHz. The measured noise figure is better than 2.5 dB below 2.1 GHz, is better than 4.5 dB below 5 GHz, and at 500 MHz, it gets its minimum value 1.8 dB. The LNA consumes 9 mA from 1.5 V supply and occupies an area of 0.04 mm2.