A 100-μW 4–6 GHz Cryogenic InP HEMT LNA Achieving an Average Noise Temperature of 2.6 K

Low-power LNAs at 4 K are critical for the scaling up of quantum computing systems due to the limited cooling capability in the dilution refrigerator. This paper presents design and fabrication of a cryogenic hybrid three-stage InP HEMT LNA working from 4 to 6 GHz. The design was conducted using a DC power optimized bias model of the InP HEMT. The 4 K measurement showed 2.6 K average noise temperature and more than 22 dB average gain of the InP HEMT LNA consuming only $100 \mu\mathrm{W}$ DC power.