Precise surface resistance measurements of YBa2Cu3Oy films with the dielectric resonator method

The surface resistance of high-T-c superconducting films at microwave frequ encies was carefully measured by the dielectric resonator method using two sapphire rods. The dielectric resonator method is appropriate for the stand ard measurement of surface resistance at microwave frequencies. In the pres ent work, we focused on asymmetry in coupling and the parasitic coupling ef fect which cause error in this method and discussed the precision and accur acy of the measurements. Finally, we report on a round robin test in which the observed surface resistances in three institutes gave good agreement. T hese results were reflected in the working draft of the International Elect rotechnical Commission Technical Committee 90 (IEC/TC90). (C) 2001 Elsevier Science B.V. All rights reserved.