A Unified Description of Nonlinear Effects in High Temperature Superconductor Microwave Devices
James C. Booth, Kenneth Leong, Susan A. Schima, Jordi Mateu, Carlos Collado, Juan M. O'Callaghan
We demonstrate experimentally the equivalence of different manifestations of nonlinear response in high temperature superconductor (HTS) microwave devices. Using a combination of analytical and numerical analysis, we show that the results of intermodulation distortion measurements, harmonic generation measurements, and power-dependent resonator measurements of different coplanar waveguide structures patterned onto the same HTS thin-film sample all yield approximately the same values for the nonlinear penetration depth. The extraction of an underlying nonlinear material parameter that is independent of the specific device geometry and experimental configuration used for nonlinear characterization should enable quantitative comparisons of the nonlinear response of different HTS materials, in order to help determine the dominant sources of nonlinear response in HTS microwave devices.