A Millimeter-Wave LNA in 45nm CMOS SOI with Over 23dB Peak Gain and Sub-3dB NF for Different 5G Operating Bands and Improved Dynamic Range

This paper presents a variable gain CMOS low-noise amplifier (LNA) with high gain and low noise figure, aiming at 5G communication. The LNA is based on a 3-stage inductively degenerated amplifier with the first stage as common-source amplifier for optimized overall noise performance, and the following two stages as cascode amplifiers for a higher gain and reverse isolation. Variable gain control with an amplification-bypass mode is implemented, facilitating the LNA/receiver to cope with the significantly different power level and thus maximizing its operation dynamic range. Two designs are implemented following the same principle, with one covering N257/258 band and the other one targeting N260 band. Both designs achieve over 23dB peak power gain with below 3dB noise figure. Variable gain control is demonstrated with more than 15dB gain tuning range over frequencies. The LNA linearity is also characterized in measurement, showing an in-band IIP3 of -9.3dBm at 24.25GHz (N257/258 LNA) and −12.9dBm at 40GHz (N260 LNA).