Observation of nonlinearity in dual-band superconducting filter using spirally asymmetric stepped-impedance resonators

In this paper, a compact dual-band high-temperature superconducting (HTS) bandpass filter is demonstrated for observing the nonlinear phenomena. Various theoretical models are applied to investigate the equivalent circuits of the proposed superconducting transmission line. To verify this methodology, the measured temperature dependence (from 65 K to 100 K) and input-power dependence(from -6 to 9 dBm) of microwave nonlinear behaviors for the dual-band HTS filter are also presented and analyzed, respectively. Measured results agree with the equivalent circuits model, which proves the accuracy of the theoretical model.