Frequency Conversion Efficiency for Highly Damped Current Controlled Josephson Junctions.

摘要

The efficiency of down conversion from a high frequency to an intermediate frequency is calculated for a current driven superconducting weak link in parallel with a resistor. Cases in which the internal,bias-controlled oscillation functions as the local oscillator and in which an external local oscillator is used are considered. The description of the former mode of operation is based on a previously published perturbation treatment of the model in the small signal limit. Accordingly the junction as free running oscillator interacts parametrically with the applied signal. The resulting 'gain'at the signal frequency is negated by the loss in the parametric conversion process to the intermediate frequency. The junction output is thus independent of the intermediate frequency. (Modified author abstract)