Power stabilized cryogenic sapphire oscillator

Author

Luiten, A.N. ; Mann, A.G. ; Costa, M.E. ; Blair, D.G.

Author_Institution

Dept. of Phys., Western Australia Univ., Nedlands, WA, Australia

Volume

44

Issue

2

fYear

1995

fDate

4/1/1995 12:00:00 AM

Firstpage

132

Lastpage

135

Abstract

Microwave oscillators of exceptional short-term stability have been realized from cryogenic sapphire resonators with loaded Q factors in excess of 10⁹ at 11.9 GHz and 6 K. This has been achieved by a power stabilized loop oscillator with active Pound frequency stabilization. These oscillators have exhibited a fractional frequency stability of 3-4×10^-15 for integration times from 0.3 to 100 s. The relative drift of these two oscillators over one day is a few times 10^-13. To reduce the long-term drift, which is principally due to excessive room temperature sensitivity, we have added cryogenic sensors for the power and frequency stabilization servos to one of these oscillators. We have also implemented a servo to reduce the room temperature sensitivity of our phase modulators. Testing of this oscillator against a Shanghai Observatory H-maser has shown an Allan deviation of 4×10^-15 from 600 to 2000 s

Keywords

cryogenic electronics; frequency stability; measurement standards; microwave oscillators; random noise; sapphire; servomechanisms; superconducting cavity resonators; 0.3 to 100 s; 11.9 GHz; 6 K; Al₂O₃; Allan deviation; H-maser; Shanghai Observatory; active Pound frequency stabilization; cryogenic sapphire oscillator; cryogenic sensors; fractional frequency stability; frequency stabilization servos; integration times; loaded Q factors; long-term drift; microwave oscillators; phase modulators; power stabilization servos; power stabilized oscillator; relative drift; room temperature sensitivity; Cryogenics; Frequency; Microwave oscillators; Observatories; Phase modulation; Q factor; Servomechanisms; Stability; Temperature sensors; Testing;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.377791

Filename

377791