Nb-based SIS mixer in the 800 GHz band

Author

Noguchi, Takashi ; Maezawa, Hiroyuki ; Shi, Sheng-Cai ; Yamamoto, Satoshi

Author_Institution

Nobeyama Radio Obs., Nagano, Japan

Volume

11

Issue

1

fYear

2001

fDate

3/1/2001 12:00:00 AM

Firstpage

167

Lastpage

170

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_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

Keywords

aluminium compounds; niobium; strip line circuits; submillimetre wave mixers; submillimetre wave receivers; superconducting device noise; superconductor-insulator-superconductor mixers; 800 GHz; 800 GHz band; 810 GHz; Al; Al striplines; DC I-V characteristics; Nb striplines; Nb-AlO-Nb; Nb-based parallel-connected twin junctions; Nb/AlO_x/Nb junctions; Nb/AlO_x/Nb waveguide SIS mixer; beam splitter; gap frequency; heterodyne mixing; noise contributions; receiver noise temperature; vacuum window; Artificial intelligence; Frequency; Niobium; Observatories; Stripline; Surface resistance; Telephony; Temperature; Waveguide discontinuities; Waveguide junctions;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.919311

Filename

919311