A Miniature 10MHz‒3GHz Sub 1-dB NF Cryogenic Inductorless Noise-Canceling Low-Noise Amplifier for Qubit Readout

This paper presents an inductorless wideband cryogenic low-noise amplifier (LNA) by the current reuse feed-forward noise canceling technique in 40-nm CMOS. The proposed LNA consists of a complementary input stage with self-forward body bias (SFBB) for low-power operation, which can also compensate for Vth reduction and improve rout under cryogenic temperature. A noise-canceling stage is used to suppress the channel noise, achieving a sub-1dB noise figure at room temperature. The LNA attains a measured gain (S21) of 25.6 dB with a minimum noise figure of 0.63 dB at 1.8 GHz. At 4K, it shows a measured gain of 29 dB with a 3-dB bandwidth across 10MHz‒3GHz under a power consumption of 19.4 mW. The circuit only occupies a core area of 0.018 mm2.