A Wide-Band High-Gain Compact SIS Receiver Utilizing a 300- $\mu$W SiGe IF LNA

Low-power low-noise amplifiers integrated with superconductor–insulator–superconductor (SIS) mixers are required to enable implementation of large-scale focal plane arrays. In this work, a 220-GHz SIS mixer has been integrated with a high-gain broad-band low-power IF amplifier into a compact receiver module. The low noise amplifier (LNA) was specifically designed to match to the SIS output impedance and contributes less than 7 K to the system noise temperature over the 4–8 GHz IF frequency range. A receiver noise temperature of 30–45 K was measured for a local oscillator frequency of 220 GHz over an IF spanning 4–8 GHz. The LNA power dissipation was only 300  $\mu$ W. To the best of the authors’ knowledge, this is the lowest power consumption reported for a high-gain wide-band LNA directly integrated with an SIS mixer.