Accurate Measurement of Gain Saturation of Superconductor–Insulator–Superconductor Mixers with Logarithmic Power Detectors
Correct measurement of the power of a continuous wave signal superimposed on a broadband noise is a presupposition for the accuracy of the gain saturation measurement of a superconductor–insulator–superconductor mixer. In practice, the response of a logarithmic power detector to a mixture of broadband noise and continuous wave signal can be unexpectedly nonlinear. This nonlinearity can cause significant error if correction is not applied.
KeywordsGain saturation Superconductor–insulator–superconductor Logarithmic power detector
Funding was provided by National Natural Science Foundation of China (Grant No. U1331203).