Title :
Frequency stable oscillators based on cryogenic whispering gallery mode resonators
Author :
Vitusevich, S. ; Winter, M. ; Klein, N.
Author_Institution :
Inst. of Thin Films & Interfaces, Forschungszentrum Julich GmbH, Germany
Abstract :
An all-cryogenic oscillator consisting of a frequency tunable sapphire resonator, a high temperature superconducting filter and a PHEMT amplifier was designed for the K-band frequency range and investigated. Sapphire whispering-gallery mode resonators possess high quality factors of about several millions due to the advantage of the strong electromagnetic field confinement. As a result the phase noise measured for the oscillator exhibits very low values in comparison to conventional oscillators. In addition, the effect of small rutile-platelets on the long-term temperature stability is measured and discussed. We have found that our composite resonators with rutile filling factor slightly below 1% exhibits a turning point in the temperature dependence of the resonance frequency at about 65-78 K. This results in a long time frequency stability as good as for oven controlled quartz oscillators by maintaining a high resonator quality factor in the 107 range at 10 GHz
Keywords :
Q-factor; circuit stability; cryogenic electronics; dielectric resonator oscillators; frequency stability; microwave oscillators; phase noise; sapphire; thermal stability; titanium compounds; variable-frequency oscillators; 10 GHz; 65 to 78 K; Al2O3; Al2O3-TiO2; K-band frequency range; PHEMT amplifier; TiO2; all-cryogenic oscillator; composite resonators; electromagnetic field confinement; frequency tunable sapphire resonator; high quality factors; high temperature superconducting filter; long time frequency stability; long-term temperature stability; phase noise; rutile filling factor; rutile-platelets; sapphire whispering-gallery mode resonators; Cryogenics; Electromagnetic measurements; Oscillators; PHEMTs; Q factor; Resonant frequency; Stability; Superconducting filters; Temperature distribution; Temperature measurement;
Conference_Titel :
Physics and Engineering of Millimeter and Sub-Millimeter Waves, 2001. The Fourth International Kharkov Symposium on
Conference_Location :
Kharkov
Print_ISBN :
0-7803-6473-2
DOI :
10.1109/MSMW.2001.946752
