Title :
A film transmission line resonator to measure the microwave surface resistance of YBa2Cu3O7-x
Author :
Martens, J.S. ; Hohenwarter, K.G. ; McGinnis, D.P. ; Beyer, J.B. ; Ginley, D.S.
Author_Institution :
Dept. of Electr. & Comput. Eng., Wisconsin Univ., Madison, WI, USA
fDate :
3/1/1989 12:00:00 AM
Abstract :
The authors constructed microstrip transmission line resonators with YBa2Cu3O6.9 ground planes, SiO dielectric, and Nb top conductors. The film resonator is a low-impedance section nλ/2 long, and the wave is launched from a coaxial line. Loose coupling is provided by the discontinuity between 50-Ω feed lines and the 0.05-Ω resonator section. After de-embedding the transmittance data of the structure, the surface resistance of the ceramic superconductor can be computed. The surface resistance of YBa2Cu3O6.9 at 4.2 K was about a factor of 60 higher than the theoretical value for Nb at 4.2 K over the range 2.9-6 GHz. The power law behavior versus frequency of the surface resistance is roughly quadratic, which is consistent with two-fluid analysis
Keywords :
barium compounds; dielectric resonators; electric resistance measurement; high-temperature superconductors; microwave measurement; strip line components; yttrium compounds; 2.9 to 6 GHz; 4.2 K; Nb-SiO-YBa2Cu3O6.9; coaxial line; film transmission line resonator; high temperature superconductor; low-impedance section; microstrip transmission line resonators; microwave surface resistance; power law behavior; transmittance data; two-fluid analysis; Conductors; Dielectric measurements; Microstrip resonators; Microwave measurements; Niobium; Power transmission lines; Superconducting transmission lines; Surface resistance; Transmission line measurements; Transmission line theory;
Journal_Title :
Magnetics, IEEE Transactions on
