A 24 - 41.5 GHz VGA With Low Phase Variation and Enhanced IIP3 for 5G Applications

Abstract

In this paper, a wide band high linearity 65-nm CMOS Variable Gain Amplifier (VGA) for millimeter-wave (mm-wave) 5G communications is presented. The VGA achieves 14 dB gain range with 1 dB gain step achieved by 9-bit digital gain control. It realizes a maximum phase variation of 2.28o, RMS phase variation of 1.64o and a maximum gain error of 0.28 dB for all gain states across the frequency range. The maximum achieved gain is 14 dB, and the worst case achieved NF is 3.3 dB at the max gain state. The VGA employs a new linearization technique to enhance the IIP3. The VGA achieves a minimum IIP3 of 12.1 dBm and 12.8 dBm at max and min gain states respectively, and a maximum IIP3 of 16.5 dBm and 18.3 dBm at max and min gain states respectively across frequency. It consumes a total power of 30 mW and occupies an area of 0.29mm2 excluding the pads.