MEASUREMENT OF SURFACE IMPEDANCE VERSUS TEMPERATURE USING A GENERALIZED SAPPHIRE RESONATOR TECHNIQUE

An automated measurement technique to measure the surface impedance, Zs=Rs+iXs, as a function of temperature is presented. Based on the dielectric resonator measurement technique, a general purpose approach is developed which does not neglect dielectric loss and can accommodate a variety of sample sizes and measurement frequencies. By employing a parallel‐plate geometry which has a known electromagnetic solution, both the surface impedance of the sample and the induced surface current can be related quantitatively to the measured Q, the resonant frequency, and the applied power. Although the measurement sensitivity depends on the system design and choice of materials, comprehensive equations are presented which serve as a useful tool for designing the system and simulating the measurement. Using a sample size of 1×1 cm2 and a measurement frequency of 19.6 GHz, a measurement uncertainty of 420 μΩ for Rs and 4800 μΩ for ΔXs is demonstrated. For superconducting samples, this translates to a measurement uncer...

[1]  D. Kajfex,et al.  Dielectric Resonators , 1986 .

[2]  Bonn,et al.  Evidence for rapid suppression of quasiparticle scattering below Tc in YBa2Cu3O7- delta. , 1992, Physical review letters.

[3]  W. E. Courtney,et al.  Analysis and Evaluation of a Method of Measuring the Complex Permittivity and Permeability Microwave Insulators , 1970 .

[4]  Charles Wilker,et al.  Surface resistance of large-area Tl2Ba2CaCu2O8 thin films at microwave and millimeter wave frequencies measured by three noncavity techniques , 1993 .

[5]  Vincent M. Hietala,et al.  Confocal resonators for measuring the surface resistance of high‐temperature superconducting films , 1991 .

[6]  U. Poppe,et al.  Microwave surface resistance of epitaxial YBa2Cu3O7 thin films at 18.7 GHz measured by a dielectric resonator technique , 1992 .

[7]  W. G. Lyons,et al.  Analysis of superconducting transmission-line structures for passive microwave device applications , 1993, IEEE Transactions on Applied Superconductivity.

[8]  D. Blair,et al.  A high-Q sapphire loaded superconducting cavity resonator , 1987 .

[9]  R. Chambers.  The anomalous skin effect , 1952, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[10]  R. C. Taber,et al.  A parallel plate resonator technique for microwave loss measurements on superconductors , 1990 .

[11]  R. Collin.  Foundations for microwave engineering , 1966 .

[12]  D. Blair,et al.  High Q tunable sapphire loaded cavity resonator for cryogenic operation , 1989 .

[13]  Zhi-Yuan Shen,et al.  High-T/sub c/-superconductor-sapphire microwave resonator with extremely high Q-values up to 90 K , 1992 .

[14]  P. R. Bevington,et al.  Data Reduction and Error Analysis for the Physical Sciences , 1969 .

[15]  E. H. Sondheimer,et al.  The evaluation of the surface impedance in the theory of the anomalous skin effect in metals , 1948, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[16]  J. Graffeuil,et al.  Microwave characterization of high Tc superconductors with a dielectric resonator , 1990 .

[17]  David Blair,et al.  Ultra-stable cryogenic sapphire dielectric microwave resonators: mode frequency-temperature compensation by residual paramagnetic impurities , 1992 .

[18]  Daniel E. Oates,et al.  Measurement of the surface resistance of YBa2Cu3O7−x thin films using stripline resonators , 1990 .

[19]  J. C. Slater,et al.  Surface impedance of normal and superconductors at 24,000 megacycles per second , 1949 .

[20]  Y. Kobayashi,et al.  Microwave measurement of temperature and current dependences of surface impedance for high-T/sub c/ superconductors , 1991 .

[21]  C. Wilker,et al.  A Sapphire Resonator for Microwave Characterization of Superconducting Thin Films , 1993, 41st ARFTG Conference Digest.