A K-band MMIC low noise amplifier in GaN-on-Si 100-nm technology for MIMO radar receivers

Abstract

A K-band low noise amplifier (LNA) with low and flat noise figure (NF) is proposed in this letter. The LNA is designed as the first stage of an RF receiver in a frequency modulated continuous wave (FMCW) multiple-in multiple-out (MIMO) radar system for marine vessel monitoring and airspace unmanned aerial vehicle (UAV) monitoring. The multi-antenna structure at the receiving end of the MIMO radar implies higher sensitivity. The LNA is fabricated using a 100-nm GaN high electron mobility transistor (HEMT) process with a chip area of 2.2mm². By analyzing the noise equivalent circuit model of a GaN-on-Si HEMT and optimizing the matching network, the proposed LNA achieves a measured average gain of 17.2dB, an NF of 2.0-2.3dB over the frequency range from 18 to 22.5GHz. With a power sweep measurement, this LNA achieves an P_1dB of 10.5dBm and an OIP₃ of 19dBm at 20GHz. The DC consumption is 220mW under 5V power supply.