Mixing characteristics of a microwave detector using a granular YBCO superconductor

• Published in: IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States) 1991-03, Vol.27 (2), p.3073-3076
• Main Authors: Yoshisato, Y., Takai, M., Niki, K., Yoshikawa, S., Hirano, T., Nakano, S.
• Format: Article
• Language: English
• Subjects: 440800 > Miscellaneous Instrumentation-- (1990-); 665411 > Basic Superconductivity Studies-- (1992-); ALKALINE EARTH METAL COMPOUNDS; AMPLITUDES; Applied sciences; BARIUM COMPOUNDS; BARIUM OXIDES; Bridge circuits; CHALCOGENIDES; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COPPER COMPOUNDS; COPPER OXIDES; CRYSTAL STRUCTURE; DATA; Detectors; ELECTRIC CONDUCTIVITY; ELECTRICAL PROPERTIES; ELECTROMAGNETIC RADIATION; ELECTRONIC EQUIPMENT; Electronics; Exact sciences and technology; EXPERIMENTAL DATA; FABRICATION; GRAIN BOUNDARIES; Granular superconductors; Hafnium; HETERODYNE RECEIVERS; INFORMATION; JOSEPHSON EFFECT; JOSEPHSON JUNCTIONS; JUNCTIONS; MICROSTRUCTURE; MICROWAVE EQUIPMENT; Microwave frequencies; MICROWAVE RADIATION; NONLINEAR PROBLEMS; NUMERICAL DATA; OTHER INSTRUMENTATION; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; RADIATIONS; RADIO EQUIPMENT; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; SENSITIVITY; Signal detection; Superconducting devices; SUPERCONDUCTING JUNCTIONS; SUPERCONDUCTIVITY; TRANSITION ELEMENT COMPOUNDS; Voltage; Yttrium barium copper oxide; YTTRIUM COMPOUNDS 665412 > Superconducting Devices-- (1992-); YTTRIUM OXIDES
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/20.133861

Microbridge-type Josephson junctions made of granular bulk YBCO superconductors were experimentally studied at microwave frequencies. Although the bridge included many grain boundaries, clear Shapiro steps were induced at every hf/2e voltage for microwave frequencies, and step height dependence for microwave power similar to that of a single weak link bridge was observed. A heterodyne mixing experiment of microwaves at about 20 GHz was also performed using the detector. The IF signal showed peak amplitudes corresponding to the peak dynamic resistance due to nonlinearity resulting from the Josephson effect. It was confirmed that the detector operates stably for the Josephson-effect heterodyne mixer at 60 K or below. The detector has potential for high sensitivity and good impedance matching due to its large dynamic resistance and high normal state resistance, respectively.