Accurate measurements of surface resistance of HTS films using a novel transmission mode Q-factor technique

Microwave characterization of HTS films, using typically a sapphire dielect ric resonator can only be as accurate as the Q(0)-factor and f(res) measure ments. A novel Transmission Mode e-Factor (TMQF) technique has been used fo r accurate measurements of surface resistance of YBa2Cu3O7 films, with erro rs lower than 1%. The method allows for accurate determination of Q(L), bet a (1), and beta (2) based on novel equations and a multi-frequency circle-f itting technique applied to S-21, S-11, and S-22 measured around the resona nce. Parasitic effects introduced by real measurement systems, namely, nois e, crosstalk, coupling loss, coupling reactance, and electrical delay due t o uncalibrated transmission lines are compensated for in the new method. Ra nge of unloaded eo-factors that can be measured with the TMQF technique is assessed to be from 100 to 10 million at the GHz range of frequencies.