Title :
Stability and phase noise tests of two cryocooled sapphire oscillators
Author :
Dick, G. John ; Wang, Rabi T.
Author_Institution :
Jet Propulsion Lab., California Inst. of Technol., Pasadena, CA, USA
Abstract :
A cryocooled compensated sapphire oscillator (CSO), developed for the Cassini Ka-band Radio Science experiment, and operating in the 7 K-10 K temperature range was previously demonstrated to show ultra-high stability of σy=2.5×10-15 for measuring times 200 seconds ⩽τ⩽600 seconds using a hydrogen maser as reference. CSO-1 and CSO-3 are now both operational with new low noise receivers. We have made initial phase noise and Allan deviation measurements that show more than ten times stability improvement over the hydrogen maser for measuring times 1 second ⩽τ⩽10 seconds, and indicate performance for the individual units of σy≈3×10-15 for measuring times from 10 to 1000 seconds. Phase noise is reduced by 20 to 28 dB over the design offset frequency range from 1 Hz to 40 Hz. Receiver design is also discussed
Keywords :
compensation; cryogenic electronics; crystal oscillators; frequency stability; microwave receivers; phase noise; radiotelescopes; sapphire; 1 to 10 s; 1 to 40 Hz; 200 to 600 s; 7 to 10 K; Al2O3; Allan deviation measurements; Cassini Radio Science experiment; Ka-band; cryocooled compensated sapphire oscillator; low noise receivers; offset frequency range; phase noise tests; stability; Frequency; Hydrogen; Masers; Noise measurement; Oscillators; Phase measurement; Phase noise; Stability; Temperature distribution; Testing;
Conference_Titel :
Frequency and Time Forum, 1999 and the IEEE International Frequency Control Symposium, 1999., Proceedings of the 1999 Joint Meeting of the European
Conference_Location :
Besancon
Print_ISBN :
0-7803-5400-1
DOI :
10.1109/FREQ.1999.841364
