GaAs HEMT low-noise cryogenic amplifiers from C-band to X-band with 0.7-K/GHz noise temperature

Cryogenic low-noise two-stage amplifiers were developed for frequency bands of 3.4-4.6 GHz, 4-8 GHz, and 8-9 GHz using commercial GaAs high electron mobility transistor. The performances are in very good agreement with simulations, and at a cryogenic temperature of 12 K, input noise temperatures get as low as 0.6 K/GHz (2.8 K for the 3.4-4.6 GHz LNA and 5 K for the 4-8 GHz and 8-9 GHz LNAs). Gain ranges from 25 to 28 dB. Ultralow noise temperature, low-power consumption, high reliability, and reproducibility make these devices adequate for series production and receiver arrays in, e.g., telescopes.