High-temperature superconducting resonators

Preliminary measurements on high-T/sub c/ superconducting resonators are reported and why they are attractive candidates for incorporation in low-noise oscillators is discussed. Some of the important contributions to oscillator noise are reviewed and how they depend on the resonator parameters is shown. A preliminary YBaCu/sub 3/O/sub 7//LaAlO/sub 3/ resonator with a Q of 9*10/sup 4/ at 6.9 GHz and 7*10/sup 4/ at 3.5 GHz has been fabricated. The temperature sensitivity, power dependence, and residual phase noise are discussed. An upper-limit on the coefficient of the 1/f component of fractional-frequency fluctuations has been measured to be -204 dB at 60 K.<
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