IEEE Transactions on Applied Superconductivity

Nb-based SIS mixer in the 800 GHz band

Takashi Noguchi, Hiroyuki Maezawa, Sheng‐Cai Shi, Satoshi Yamamoto

Published Mar 1, 2001• 6 citations

Abstract

We have built a waveguide SIS mixer with Nb-based parallel-connected twin junctions at 800 GHz which is above the gap frequency of Nb (690 GHz). Heterodyne mixing was performed at 810 GHz and a receiver noise temperature of 580 K (DSB), which includes noise contributions due to a vacuum window and a beam splitter, was achieved using Nb/AlO/sub x//Nb junctions with Nb striplines. The performance of this mixer is quite good and it is shown that efficient mixing in Nb-based SIS junctions is still possible above the gap frequency, SIS mixers with Al striplines have also been fabricated and good DC I-V characteristics have been observed. Heterodyne measurements of these mixers are now under preparation.

DOI: 10.1109/77.919311

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