DocumentCode :
3198451
Title :
Advanced phase noise suppression technique for next generation of ultra low-noise microwave oscillators
Author :
Ivanov, E.N. ; Tobar, M.E. ; Woode, R.A.
Author_Institution :
Dept. of Phys., Western Australia Univ., Nedlands, WA, Australia
fYear :
1995
fDate :
31 May-2 Jun 1995
Firstpage :
314
Lastpage :
320
Abstract :
In this paper we report an advanced phase noise reduction technique developed to improve the short term frequency stability of the microwave oscillators. The technique is based upon the ultra sensitive microwave frequency discriminator with the effective noise temperature close to its physical temperature. The frequency discriminator comprises a room temperature sapphire loaded cavity operating on a “whispering gallery” mode with an unloaded Q factor of 185000 at 9 GHz. The phase noise spectral density of the microwave loop oscillator, incorporating such a discriminator as a sensor for the frequency servo, has been measured to be equal to Sφosc(F)≈-60-10log10(F3 ) dBc/Hz at frequencies below a few kHz. This corresponds to a level of phase noise as low as -120 dBc/Hz and -150 dBc/Hz at offset frequencies 100 Hz and 1 kHz respectively
Keywords :
cavity resonators; circuit noise; discriminators; frequency stability; interference suppression; microwave oscillators; phase noise; 9 GHz; frequency servo; microwave frequency discriminator; microwave loop oscillator; phase noise spectral density; phase noise suppression technique; room temperature sapphire loaded cavity; short term frequency stability; ultra low-noise microwave oscillators; whispering gallery mode; Density measurement; Microwave frequencies; Microwave oscillators; Microwave sensors; Microwave theory and techniques; Phase noise; Q factor; Servomechanisms; Stability; Temperature sensors;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Frequency Control Symposium, 1995. 49th., Proceedings of the 1995 IEEE International
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-2500-1
Type :
conf
DOI :
10.1109/FREQ.1995.483916
Filename :
483916
Link To Document :
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