Title :
Niobium SIS mixers at 490 GHz, 690 GHz and 810 GHz
Author :
Honingh, C.E. ; Jacobs, K. ; Haas, S. ; Hottgenroth, D. ; Stutzki, J.
Author_Institution :
I. Phys. Inst., Koln Univ., Germany
fDate :
6/1/1995 12:00:00 AM
Abstract :
Low noise mixers are developed for a dual channel heterodyne receiver for astronomical applications which will operate alternatingly in two of three the frequency bands 460-490 GHz, 660-690 GHz, and 800-850 GHz. As mixing elements Nb-Al/sub 2/O/sub 3/-Nb (SIS) tunnel junctions are used, fabricated at the University of Cologne with integrated RF and IF circuitry, also made of niobium. The frequency dependent RF-properties of the circuitry are calculated for all bands using Mattis-Bardeen theory in the extreme anomalous limit. The circuits are optimized for a large instantaneous receiver bandwidth to facilitate the use of waveguide type mixer mounts without mechanical tuners. Results on receiver noise, stability and design accuracy will be presented.<>
Keywords :
niobium; submillimetre wave mixers; submillimetre wave receivers; superconducting device noise; superconductor-insulator-superconductor mixers; 460 to 490 GHz; 660 to 690 GHz; 800 to 850 GHz; Mattis-Bardeen theory; Nb-Al/sub 2/O/sub 3/-Nb; Nb-Al/sub 2/O/sub 3/-Nb tunnel junctions; RF-properties; astronomical applications; bandwidth; circuit optimization; design; dual channel heterodyne receiver; integrated RF-IF circuitry; low noise mixers; mechanical tuners; niobium SIS mixers; stability; waveguide type mixer mounts; Bandwidth; Circuit optimization; Circuit testing; Frequency; Niobium; Receiving antennas; Superconducting device noise; Temperature; Tuning; Waveguide junctions;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
