Characterization of X-band filter of double-sided Y-Ba-Cu-O film on MgO substrate

We investigated the pulsed laser deposition process of double-sided Y-Ba-Cu-O thin films on MgO substrates, the critical current density (Jc) distribution and the microwave surface impedance (Rs) of the films, and the power handling capability by third-order intermodulation distortion (IMD3) measurements using 40 W high power microwave measurement system. A clean flat MgO surface was important for Y-Ba-Cu-O deposition and successfully obtained by three-hour pre-annealing at 1000°C in air. To confirm the film process, we designed, fabricated and measured the 11 GHz band-pass 7-pole Y-Ba-Cu-O filter. We also found that the outskirts of the Y-Ba-Cu-O film on MgO substrate were particularly important in Jc quality because the biggest microwave power in filter circuit is allocated in the outskirts of Y-Ba-Cu-O film area