Contents I. Introduction
The SQA appears to be a good choice as rf amplifier for ultra low-noise applications within frequency range of a few GHz. The SQA has a number of advantages compared to traditional semiconductor amplifiers: nearly quantum limited noise, which can be reduced to the mK level via deep cooling [1], ultra-low power consumption, small size and natural integration compatibility with many superconducting detectors and signal processing structures. Our study of multi-channel SQA is a logical step toward integration of superconducting rf devices that simultaneously can minimize noise, heat and packaging problems for future superconducting rf detectors. The SQA is a promising device at least for the following applications: i) IF amplification after a SIS-mixer and especially for imaging array mixers including a Superconducting Integrated Receiver with phase-locked loop [2]; ii) rf pre-amplifier for RSFQ ADC; iii) amplifier for mobile and satellite communications.
