Title :
Phase noise of a tunable and fixed frequency sapphire loaded superconducting cavity oscillator
Author :
Tobar, M.E. ; Blair, D.G.
Author_Institution :
Western Australia Univ., Nedlands, WA, Australia
Abstract :
The measured phase noise of two GaAs FET amplifiers and a varactor phase shifter at 9.7 GHz reveal that optimum FET and diode bias voltage changes when cooling from room to liquid helium temperatures. This understanding enables optimization of the noise in all-cryogenic sapphire-loaded superconducting cavity X-band loop oscillator. It is shown that one can reduce the current measured oscillator noise of -120 dBc/Hz at 1 kHz by 20 to 45 dB.<>
Keywords :
cavity resonators; field effect transistors; microwave oscillators; superconducting microwave devices; varactors; variable-frequency oscillators; 9.7 GHz; FET amplifiers; X-band loop oscillator; bias voltage; fixed-frequency sapphire-loaded cavity; oscillator noise; phase noise; superconducting cavity oscillator; tunable oscillator; varactor phase shifter; FETs; Frequency; Gallium arsenide; Noise measurement; Oscillators; Phase measurement; Phase noise; Phase shifters; Superconducting device noise; Varactors;
Conference_Titel :
Microwave Symposium Digest, 1992., IEEE MTT-S International
Conference_Location :
Albuquerque, NM, USA
Print_ISBN :
0-7803-0611-2
DOI :
10.1109/MWSYM.1992.188017
