Title :
A 100 GHz Josephson mixer using resistively-shunted Nb tunnel junctions
Author :
Schoelkopf, R.J. ; Phillips, T.G. ; Zmuidzinas, J.
Author_Institution :
Downs Lab. of Phys., California Inst. of Technol., Pasadena, CA, USA
fDate :
3/1/1993 12:00:00 AM
Abstract :
The authors describe preliminary mixer results using resistively shunted Nb/AlO/sub x//Nb tunnel junctions in a 100-GHz waveguide mixer mount. The mixer utilizes robust, lithographically defined devices which have nonhysteretic I-V curves. A receiver temperature of 390 K (D5B) has been obtained with a conversion loss of -6.5 dB. The receiver´s behavior agrees qualitatively with the behavior predicted by the resistively shunted junction model. Substantial improvements in performance are expected with the use of better-optimized shunted junctions and numerical simulations suggest that, if devices with higher I/sub C/R/sub N/ (critical-current normal-resistance) products can be obtained. Josephson effect mixers could be competitive with superconductor-insulator-superconductor (SIS) mixers at high frequencies.<>
Keywords :
Josephson effect; critical currents; microwave detectors; mixers (circuits); niobium; receivers; superconducting junction devices; superconducting microwave devices; type II superconductors; -6.5 dB; 100 GHz; 390 K; Josephson mixer; Nb tunnel junctions; Nb-AlO/sub 2/-Nb; conversion loss; critical current-resistance product; heterodyne response; lithographically defined devices; receiver temperature; resistively shunted junction model; resistively-shunted; waveguide mixer mount; Frequency; Josephson effect; Josephson junctions; Niobium; Numerical simulation; Predictive models; Robustness; Superconducting devices; Temperature; Waveguide junctions;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
