A Study on Ultra-Wideband Negative Feedback Cryogenic Amplifier with High Sensitivity and Low Noise

In this paper, a three-stage cascaded ultra-wideband cryogenic and low-noise amplifier is designed based on the high electron mobility transistor MGF4941AL with an operating frequency range from 1.3 GHz to 8 GHz. The π-type matching, T-type matching and parallel RLC negative feedback are introduced to achieve ultra-wideband. The final results of the amplifier show that the gain is 32.5±1.94 dB at 298.15 K room temperature, the noise figure is less than 4.2 dB, S11 and S22 are less than -10dB in the frequency band of 1.3 GHz-8 GHz, the sensitivity is less than -51.5 dBm, with the stability coefficient is greater than 2.03, which achieves stable operation in the frequency band. The noise figure is less than 0.25 dB and the sensitivity is less than -64.1 dBm at 20 K low temperature.