Title :
High-Q TE stabilized sapphire microwave resonators for low noise applications
Author :
Tobar, M.E. ; Giles, A.J. ; Edwards, S. ; Searls, J.
Author_Institution :
Dept. of Phys., Univ. of Western Australia, Nedlands, WA, Australia
Abstract :
Two low-noise high-Q sapphire loaded cavity (SLC) resonators, with unloaded Q values of 2 × 105 and very low densities of spurious modes have been constructed. They were designed to operate at 0°C with a center frequency of 10.000000 GHz. The cavity was cooled with a thermoelectric (TE) Peltier element and in practice achieved the required center frequency near 1°C. The resonator has a measured frequency-temperature coefficient of -0.7 MHz/K and a Q-factor which is measured to be proportional to T2.5. An upper limit to the SLC residual phase noise to L(100 Hz) = -147.5 dBc/Hz, L(1 kHz) = -155 dBc/Hz, and L(10 kHz) = -160 dBc/Hz has been measured. The authors have created a free running loop oscillator based on the SLC resonator and measured its frequency noise using the other as a discriminator
Keywords :
Q-factor; cavity resonators; feedback oscillators; microwave oscillators; phase noise; sapphire; 10 GHz; Al2O3; Q-factor; SLC residual phase noise; SLC resonator; TE stabilized sapphire microwave resonators; discriminator; free running loop oscillator; frequency noise; frequency-temperature coefficient; sapphire loaded cavity resonators; spurious modes; thermoelectric Peltier element; Dielectric losses; Frequency measurement; Instruments; Local oscillators; Q factor; Resonance; Resonant frequency; Tellurium; Temperature; Voltage control;
Conference_Titel :
Frequency Control Symposium, 1993. 47th., Proceedings of the 1993 IEEE International
Conference_Location :
Salt Lake City, UT
Print_ISBN :
0-7803-0905-7
DOI :
10.1109/FREQ.1993.367473
