Externally phase-locked flux flow oscillator for submm integrated receivers: achievements and limitations

Author

Koshelets, Valery P. ; Shitov, Sergey V. ; Dmitriev, Pavel N. ; Ermakov, Andrey B. ; Sobolev, Alexander S. ; Torgashin, Mikhail Yu ; Khodos, Victor V. ; Vaks, Vladimir L. ; Wesselius, Paul R. ; Yagoubov, Pavel A. ; Mahaini, Carsten ; Mygind, Jesper

Author_Institution

Inst. of Radio Eng. & Electron., Russian Acad. of Sci., Moscow, Russia

Volume

13

Issue

2

fYear

2003

fDate

6/1/2003 12:00:00 AM

Firstpage

1035

Lastpage

1038

Abstract

A Josephson flux flow oscillator (FFO) is the most developed superconducting local oscillator for integration with an SIS mixer in a single-chip submm-wave receiver. Recently, using a new FFO design, a free-running linewidth ≤10 MHz has been measured in the frequency range up to 712 GHz, limited only by the gap frequency of Nb. This enabled us to phase lock the FFO in the frequency range 500-712 GHz where continuous frequency tuning is possible; resulting in an absolute FFO phase noise as low as -80 dBc at 707 GHz. Comprehensive measurements of the FFO radiation linewidth have been performed using an integrated SIS harmonic mixer. The influence of FFO parameters on radiation linewidth, particularly the effect of the differential resistances associated both with the bias current and the applied magnetic field has been studied in order to further optimize the FFO design. A new approach with a self-shielded FFO has been developed and experimentally tested.

Keywords

flux flow; phase locked oscillators; submillimetre wave receivers; superconductor-insulator-superconductor devices; 500 to 712 GHz; Josephson flux flow oscillator; SIS mixer; bias current; continuous frequency tuning; differential resistances; externally phase-locked flux flow oscillator; free-running linewidth; gap frequency; harmonic mixer; radiation linewidth; submm integrated receivers; superconducting local oscillator; Electrical resistance measurement; Frequency measurement; Local oscillators; Magnetic field measurement; Niobium; Noise measurement; Phase measurement; Phase noise; Superconducting devices; Tuning;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2003.814144

Filename

1211783