Performance limits of the Josephson junction microwave receivers

The performance limits are found for the Josephson junction microwave receivers: self- and externally-pumped mixers, as well as self-selecting and wideband quadratic detectors. The effect of the signal source impedance upon the Josephson junction properties is considered in two extreme approximations for the junc-, tion matching with the source, the approximations yielding close results. It has become possible to find the device characteristics for the arbitrary values of ratios RE/RNand F/Fc, where REis the reduced source resistance, RNis the junction normal resistance, F is the signal frequency and FCis the junction characteristic frequency. The performance factors obtained are optimized and their ultimate limits are found. The relatively poorly-developed devices without external pumping (self-pumped mixer and self-selecting detector) occur to have the best performance limits. Achievement of these limits is possible, however, only if the recently proposed specially-designed multi-junction arrays are used.