Article ID: 19.20220454
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 2.2 mm2. 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 17.2 dB, an NF of 2.0-2.3 dB over the frequency range from 18 to 22.5 GHz. With a power sweep measurement, this LNA achieves an P1dB of 10.5 dBm and an OIP3 of 19 dBm at 20 GHz. The DC consumption is 220 mW under 5 V power supply.
