Title :
Hot electron quasioptical NbN superconducting mixer
Author :
Karasik, B.S. ; Gol´tsman, Gregory N. ; Voronov, B.M. ; Svechnikov, S.I. ; Gershenzon, E.M. ; Ekstrom, H. ; Jacobsson, S. ; Kollberg, E. ; Yngvesson, K.S.
Author_Institution :
Moscow State Pedagogical Univt., Russia
fDate :
6/1/1995 12:00:00 AM
Abstract :
Hot electron superconductor mixer devices made of thin NbN films on SiO/sub 2/-Si/sub 3/N/sub 4/-Si membrane have been fabricated for 300-350 GHz operation. The device consists of 5-10 parallel strips each 5 /spl mu/m long by 1 /spl mu/m wide which are coupled to a tapered slot-line antenna. The I-V characteristics and position of optimum bias point were studied in the temperature range 4.5-8 K. The performance of the mixer at higher temperatures is closer to that predicted by theory for uniform electron heating. The intermediate frequency bandwidth versus bias has also been investigated. At the operating temperature 4.2 K a bandwidth as wide as 0.8 GHz has been measured for a mixer made of 6 nm thick film. The bandwidth tends to increase with operating temperature. The performance of the NbN mixer is expected to be better for higher frequencies where the absorption of radiation should be more uniform.<>
Keywords :
bolometers; hot carriers; niobium compounds; submillimetre wave mixers; superconducting junction devices; superconducting microwave devices; 0.8 GHz; 300 to 350 GHz; 4.2 K; 4.5 to 8 K; I-V characteristics; NbN-SiO/sub 2/-Si/sub 3/N/sub 4/-Si; SiO/sub 2/-Si/sub 3/N/sub 4/-Si membrane; bolometric mixer; hot electron superconducting mixer; intermediate frequency bandwidth; operating temperature; optimum bias point; quasioptical superconducting mixer; submillimeter wave mixer; tapered slot-line antenna; thin NbN films; uniform electron heating; Bandwidth; Biomembranes; Electrons; Frequency; Heating; Slot antennas; Superconducting devices; Superconducting films; Temperature distribution; Thickness measurement;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
