Title :
High-Tc-superconductor-sapphire microwave resonator with extremely high Q-values up to 90 K
Author :
Shen, Zhi-Yuan ; Wilker, Charles ; Pang, Philip ; Holstein, William L. ; Face, Dean ; Kountz, Dennis J.
Author_Institution :
E.l. DuPont de Nemours & Co. Inc., Wilmington, DE, USA
fDate :
12/1/1992 12:00:00 AM
Abstract :
A theoretical analysis was performed for an extremely high-Q resonator formed by a sapphire rod sandwiched by a pair of high- Tc superconductor (HTS) films. A number of these HTS-sapphire-HTS resonators at C-band and Ka-band were designed, fabricated, and tested. At 5.552 GHz, Q0 reached 2×106 at 90 K, 3×106 at 80 K and 1.4×107 at 4.2 K with circulating power up to 500 kW. Formulas for calculating the resonant frequency and Q-value derived from the theoretical analysis were verified by experimental data with good agreement. Three different thin-film HTS materials-Tl2 Ba2CaCu2O8, YBa2Cu3O7-δ and Tl0.5Pb0.5Sr2CaCu2O7 -were tested. The sensitivity of the high Q-value and the parasitic coupling to the case modes are discussed. Applications such as frequency stabilized oscillators, filters, and HTS film characterization are described
Keywords :
Q-factor; high-temperature superconductors; resonators; sapphire; solid-state microwave devices; superconducting microwave devices; superconducting thin films; 4.2 to 90 K; 5.552 GHz; 500 kW; C-band; Ka-band; Tl0.5Pb0.5Sr2CaCu2O 7-Al2O3; Tl2Ba2CaCu2O8-Al 2O3; YBa2Cu3O7-Al2O3 ; film characterization; filters; frequency stabilized oscillators; high-Q resonator; high-Tc superconductor films; microwave resonator; sapphire rod; thin-film; Copper; Frequency; High temperature superconductors; Microwave filters; Microwave oscillators; Superconducting films; Superconducting filters; Superconducting microwave devices; Surface resistance; Testing;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
