Development of a waveguide NbN-based SIS mixer in the 900-GHz band

Author

Takeda, Masanori ; Uzawa, Yoshinori ; Wang, Zhen ; Saito, Atsushi ; Kawakami, Akira

Author_Institution

Kansai Adv. Res. Center, Commun. Res. Lab., Kobe, Japan

Volume

13

Issue

2

fYear

2003

fDate

6/1/2003 12:00:00 AM

Firstpage

692

Lastpage

695

Abstract

We have designed and fabricated waveguide superconductor-insulator-superconductor (SIS) receivers at 870 GHz with NbN/AlN/NbN tunnel junctions on an MgO substrate. A waveguide probe was incorporated into the mixer chip for a waveguide-to-microstrip transition. As the tuning circuit for the SIS mixer, we designed a resonant distributed junction whose length is one wavelength and critical current density is 20 kA/cm². The mixing properties were calculated based on the quantum theory of mixing. The SSB mixer noise temperature should be less than 100 K and conversion gain larger than -8.0 dB in the frequency range from 840 to 920 GHz. We also observed the resonance steps of the fabricated SIS mixer. The tuning frequency was slightly higher than the designed frequency.

Keywords

circuit tuning; critical current density (superconductivity); microstrip transitions; niobium compounds; submillimetre wave mixers; superconductor-insulator-superconductor mixers; waveguide transitions; -8.0 dB; 840 to 920 GHz; MgO; MgO substrate; NbN-AlN-NbN; NbN/AlN/NbN tunnel junction; SSB mixer noise temperature; critical current density; quantum theory; resonant distributed junction; terahertz band; tuning circuit; waveguide SIS mixer; waveguide probe; waveguide-to-microstrip transition; Circuit optimization; Frequency; Josephson junctions; Mixers; Probes; RLC circuits; Resonance; Superconducting devices; Waveguide junctions; Waveguide transitions;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2003.814003

Filename

1211697