高温超导共面波导功率非线性研究及测试

The power-dependent nonlinearity research and measurements of high-temperature superconductor CPW transmission line

采用临界电流密度与仿真相结合，预估了共面波导微波强非线性测试系统的功率要求．该方法理论值为30dBm，与实测临界功率26～27dBm相近，表明该方法可行．该法可能有助于超导机理的研究．同时发现，在高于临界功率时，表面电阻随传输特性发生陡变．该结果有助于开发超宽带、低损耗超导微波限幅器和开关．

This paper uses the combination of critical current density and the simulation to estimate the microwave power requirement of the measurement system for the microwave strong nonlinearity of the coplanar waveguide transmission line. The estimated value is 30 dBm and is close to the tested value between 26--27 dBm, which implies that the estimating method is effective, and this method is helpful to the research of the inner mechanism of superconductivity nonlinearity. At the same time, we find the surface resistance varied sharply at the critical power. This result is helpful to develop ultra wide band, low loss superconducting microwave limiters and switches.