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Measurement and analysis of a microwave oscillator stabilized by a sapphire dielectric ring resonator for ultra-low noisePhase-noise measurements are presented for a microwave oscillator whose frequency is stabilized by a whispering-gallery sapphire ring resonator with Q of 200,000. This mode involves little metallic conduction and allows nearly full use of the very low dielectric loss in sapphire. Several mode families have been identified, in good agreement with frequency calculations. For a 5-cm wheel resonator in a 7.6-cm container, Q values above 100,000 were found at room temperature for all of the modes in this sequence. Coupling Q-values for these same modes ranged from 10,000 (n = 5) to 100,000 (n = 10) for a WR112 waveguide port at the center of the cylinder wall of the containing can. Phase noise measurements for a transistor oscillator locked to the n = 10 (7.84-GHz) mode showed a 1/f cubed dependence for low offset frequencies, and a value of L(f) = -55 dB/Hz at an offset of 10 Hz from the carrier.
Document ID
19900064020
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Dick, G. John
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Saunders, Jon
(JPL Pasadena, CA, United States)
Date Acquired
August 14, 2013
Publication Date
September 1, 1990
Publication Information
Publication: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Volume: 37
ISSN: 0885-3010
Subject Category
Electronics And Electrical Engineering
Accession Number
90A51075
Distribution Limits
Public
Copyright
Other

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