A 20-GHz 1.9-mW LNA Using g m-Boost and Current-Reuse Techniques in 65-nm CMOS for Satellite Communications

Abstract

A 20-GHz low-power low-noise amplifier (LNA) in 65-nm CMOS is presented. The LNA is cascaded with a single-ended $g_{\mathrm {m}}$ -boosted common-gate (CG) stage and a differential neutralized common-source (CS) stage. Current-reuse technique is employed to save the power consumption with little deterioration in gain and noise figure (NF). The transformer-based $g_{\mathrm {m}}$ -boost technique in the CG stage and neutralization technique in CS stage further enhances the RF performances. Inter-stage magnetically coupled resonator (MCR) extends the bandwidth. An elaborate analysis of the current-reused CG–CS LNA using a transformer-based $g_{\mathrm {m}}$ -boost technique and transformer-based MCR is proposed. Fabricated in 65-nm CMOS technology, the LNA achieves a measured power gain of 14.9 dB at 21 GHz with a −3-dB bandwidth of 4.8 GHz. The lowest NF is 3.3 dB at 19.5 GHz and is below 4 dB from 17 to 21 GHz. The LNA consumes 1.9 mW from a 1-V supply, with a chip area of 600 $\mu \text{m}\,\,\times $ 700 $\mu \text{m}$ .