Browse > Article

Microwave Properties of HTS Parallel-Plate Sapphire Resonators Designed for the Two-Resonance Mode Method  

Jung, Ho-Sang (Department of Physics and Center for Wireless Transmission Technology, Konkuk University)
Yang, W.I. (Department of Physics and Center for Wireless Transmission Technology, Konkuk University)
Lee, J.H. (SuNAM Co., Ltd)
Lee, Sang-Young (Department of Physics and Center for Wireless Transmission Technology, Konkuk University)
Publication Information
Progress in Superconductivity / v.11, no.2, 2010 , pp. 106-111 More about this Journal
Abstract
Sapphire resonators with $YBa_2Cu_3O_{7-\delta}$ (YBCO) endplates have provided a way to realize extremely high quality factor due to the extremely low dielectric loss of sapphire and conductive loss of YBCO films, which enables to measure the low surface resistance of superconductor films at microwave frequencies. We present microwave properties of HTS sapphire resonators designed for measuring the surface resistance of HTS films at millimeter-wave frequencies by using the two-resonance mode dielectric resonator method. Despite enhanced surface resistance ($R_S$) of YBCO films due to the quadratic frequency dependence of the $R_S$, the unloaded quality factor ($Q_0$) of the $TE_{021}$ mode sapphire resonator still appears to be well above $1\;{\times}\;10^6$ at a mm-wave frequency of 38 GHz at 10 K. However, it appears that the $TE_{012}$ mode $Q_0$ is unexpectedly low despite that the corresponding resonance peak looks uncoupled with parasitic modes. We discuss possible reasons for the unexpected results using the surface resistance at the $TE_{021}$, $TE_{012}$, and $TE_{011}$ mode frequencies.
Keywords
Sapphire resonator; Two-resonance mode; Microwave; Surface resistance; Superconductor;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 Z Y Shen, C Wiler, P Ang, W L Holstein, D Face and D J Kountz, "High Tc Superconductor_sapphire microwave resonator with extremely high Q_values up to 90K", IEEE Trans. On Microwave Theory and Tech, 40, 2424-2432 (1992).   DOI   ScienceOn
2 J. H. Lee, W. I. Yang, M. J. Kim, J. C. Booth, K. Leong, S. Schima, D. Rudman, S. Y. Lee "Accurate measurements of the intrinsic surface impedance of thin $YBa_2Cu_3O_{7-{\delta}}$ films using a modified two-tone resonator method", IEEE Trans. Applied Supercond. 15, 3700-3704 (2005).   DOI   ScienceOn
3 See e.g., J. H. Lee, H. K. Han, and S. Y. Lee, "Effects of the temperature-dependent dielectric constant on the geometrical factors of dielectric resonators and the measurement accuracy in the surface resistance of superconductor films", J. Korean Phys. Soc. 47, 494-500 (2005)
4 See e.g., the website for Theva (http://www.theva.com/)
5 D Kajfez and P Guillion, "Dielectric resonators", 2nd ed, Noble, Chap 5 (1998)
6 J. Krupka, D. Derzakowski, M. Tobar, J. Hartnett, and R. G. Geyer, Meas. Sci. Technol. 10, 387 (1999).   DOI   ScienceOn
7 J Krupka et al., "Surface resistance measurements of HTS films by means of sapphire dielectric resonators", IEEE Trans. on Applied Superconductivity, 3, 3043-3048 (1993).   DOI   ScienceOn
8 J Mazierska and C. Wilker, "Accuracy issues in surface resistance measurements of high temperature superconductor using dielectric resonators", IEEE Trans. Appl. Supercond. 11, 4140 (2001).   DOI   ScienceOn
9 H J Kwon, J Hur and S Y Lee, "Accurate measurements of the unloaded Q of a dielectric-loaded high-Q $TE_{01{\delta}}$ mode cavity resonator with HTS endplates", Progress in Superconductivity, 1 (1), 36-41 (1999).
10 Y Kobayashi and H. Yoshikawa, "Microwave measurements of surface impedance of high-TC superconductors using two modes in a dielectric rod resonator", IEEE Trans. Microwave Theory Tech., 46, 2524-2530 (1998).   DOI   ScienceOn
11 M. Hein, High-Temperature Superconductor Thin Films at Microwave Frequencies (Springer-Verlag, Berlin and Heidelberg, 1999), Chap. 2.
12 Y Kobayashi, T Imai and H Kayano, "Microwave measurement of temperature and current dependences of surface impedance for high-TC superconductors", IEEE Trans. on Microwave Theory and Tech., 39, 1530-1538 (1991).   DOI   ScienceOn
13 See e.g., S. Y. Lee, J. H. Lee, J. H. Han, S. H. Moon, H. N. Lee, J. C. Booth, J. H. Claassen, "Effects of the two-gap nature on the microwave conductivity of polycrystalline $MgB_2$ films with the critical temperature of 39 K", Phys. Rev. B 71, 104514 (2005)   DOI   ScienceOn
14 See e.g., S. Y. Lee and B. Oh, "Recent progress in microwave HTS technologies in Korea and Japan", J. Supercond. 16, 823-831 (2003)   DOI   ScienceOn