6-7 GHz Cryogenic Low-Noise mHEMT-Based Amplifier for Quantum Computing

A C-band cryogenic MMIC low-noise amplifier (LNA) was designed and fabricated using a 70 nm GaAs metamorphic high electron mobility transistor (mHEMT) process for quantum computing. The input impedance of the LNA was transformed to the optimum noise match of the transistor. At ambient temperature 10 K, the minimum noise temperature was 4.5 K at 6.3 GHz and below 5.0 K within the entire 6.0-7.0 GHz band.