HTS cavities for low phase noise oscillator applications

Author

Button, T.W. ; Smith, P.A. ; Alford, N.M. ; Greed, R.B. ; Adams, M.J. ; Nicholson, B.F.

Author_Institution

Birmingham Univ., UK

Volume

7

Issue

2

fYear

1997

fDate

6/1/1997 12:00:00 AM

Firstpage

3064

Lastpage

3066

Abstract

The origins of phase noise in oscillator systems are reviewed. A simple, self-excited 7.5 GHz oscillator incorporating either a conventional metal cavity resonator or a high temperature superconducting (HTS) cavity has been produced. Comparative measurements made at 77 K demonstrate significant improvements in the close-to-carrier noise performance of the oscillator incorporating the HTS cavity; 10 dB at a 10 kHz offset rising to more than 25 dB at a 10 Hz offset. The unloaded Q of the HTS cavity doubled to >10/sup 6/ on cooling from 77 K to 64 K suggesting that further improvements in noise performance could be achieved.

Keywords

Q-factor; barium compounds; flicker noise; high-temperature superconductors; microwave oscillators; phase noise; superconducting cavity resonators; superconducting device testing; yttrium compounds; 64 to 77 K; 7.5 GHz; HTS cavities; YBa/sub 2/Cu/sub 3/O/sub 7/; close-to-carrier noise performance; high temperature superconducting cavity; low phase noise oscillator; metal cavity resonator; noise performance improvement; self-excited oscillator; unloaded Q; 1f noise; Atmospheric measurements; Bandwidth; Cavity resonators; Circuit noise; High temperature superconductors; Noise measurement; Oscillators; Phase noise; Superconducting device noise;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.621979

Filename

621979