The microwave properties of the double-sided thin film MgB2 resonator

Double-sided magnesium diboride (MgB2) thin films have been grown on double-sided polished sapphire substrates by the technique of hybrid physical chemical vapor deposition (HPCVD). The zero resistance temperature (Tc) of the films is higher than 37 K. The microwave characteristic of the double-sided MgB2 thin films at 8.7GHz is studied systematically by the microstrip resonator technique. Surface resistance of the thin films is extracted by analyzing the resonance curves at different temperatures, and it is 1.2 mΩ at 11K.