Cryogenic 2-4 GHz ultra low noise amplifier

This paper describes two-stage InP-based cryogenic broadband amplifier with very low noise for the frequency band 1.5-4.5 GHz. For a band of 2-4 GHz at 15 K the measured gain is 30.0/spl plusmn/2 dB and a noise temperature below 5 K. The total DC power consumption of the amplifier is 6.8 mW.