A 2.5-2.6 dB Noise Figure LNA for 39 GHz band in 22 nm FD-SOI with Back-Gate Bias Tunability

Abstract

This paper presents a 2-stage low-noise amplifier (LNA) designed in 22 nm fully-depleted silicon-on-insulator (FD-SOI) technology, covering the N259 and N260 millimeter-wave 5G bands. The prototype features 19.9 dB peak gain, 2.5-2.6 dB noise figure (NF) and 6.6 GHz bandwidth (intersection of 3 dB gain flatness and -10 dB input/output matching), -5.4 dBm third-order input intercept point (IIP3) for a 20.8 mW power dissipation. Modulating the back-gate bias of each stage independently switches the LNA operation mode from a combination of low-noise (0.8 dB variation in NF), high-linearity <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\sim 3$</tex> dB variation in IIP3) and/or low-power (down to 7.4 mW). Finally, a careful noise contribution analysis of the input matching identifies a 0.58 dB main contribution from the input spiral inductor. EM simulations show that a 0.06 dB improvement in NF can be achieved by using a high-resistivity substrate, if the input inductor design is optimized by stacking several metal layers.