Design and Fabrication of Cryogenic Low Noise Amplifier in Low RL band

A low noise amplifier (LNA) has been designed and fabricated with high performance at cryogenic temperature. The scattering parameters of the key passive elements were characterized at room and cryogenic temperatures in order to provide data for designing the LNA. The combination of the source reflection coefficient Gamma_S and the load reflection coefficient Gamma_L was optimized. The measurement shows that at cryogenic temperature the noise figure is lower than 0.45 dB, the gain is 22 dB, the maximum input/output return loss is better than -15 dB and the minimum output P_{-1 dB} is above 14 dBm in the band range from 580 MHz to 620 MHz .