The power-dependent test of high temperature superconductor CPW transmission line

This paper presents a fabricated coplanar waveguide transmission line based on high-temperature superconductor thin-films (HTS), whose power-dependent performance is also tested here. We find that if the input is switched from low power to high power, i.e., the microwave current in the CPW line exceeds critical value, the transmission line transits from low-loss superconducting state to high-loss normal state at 77 K in liquid nitrogen, The power-dependent measurement is made in 2-5 GHz using 200 MHz frequency interval, and the critical power at each frequency is between 27-28 dBm. the surface impedance varies steeply from low level to high when transferred power reaches the critical value. This device is hopeful to be a microwave power limiter and the test result is useful for the development of the microwave power limiter.