RF Power Properties of YBCO-Film/LAO Microstrip Disk Resonators for 4 GHz Band

This paper presents RF power properties of YBCO films on LaAlO3 substrate examined using microstrip disk shape-patterned resonators for around 4 GHz. Characterization of the YBCO films for the resonators was carried out. For input-output power measurement, the resonators with the condition of strong I/O couplings were designed and fabricated. The RF power properties of the resonators at cryogenic temperatures were measured. The resonator condition to obtain the handling power over 10 W at 30 and 70 K was confirmed. The temperature dependence of the break-down powers at 4 GHz for the resonators showed two broad peaks. We discuss the unique phenomenon with magnetic flux model, as referred to the YBCO films characteristics results. key words: YBCO, LAO, RF, power, disk, resonator