An ultra-broadband robust LNA for defence applications in AlGaN/GaN technology

The design, fabrication and test of a 2-18 GHz monolithic Low Noise Amplifier utilizing 0.25 μm AlGaN/GaN HEMT technology is reported. The measured noise figure of the amplifier is less than 4.7 dB over the 2 - 18 GHz frequency range, exhibiting a minimum of 3.3 dB at 3 GHz. The LNA gain is 23 dB. Even being a low-noise amplifier, the MMIC can withstand 10W input CW RF power, demonstrating no apparent degradation: to the authors knowledge this is the best RF LNA survivability reported to date in this frequency range using GaN technology.