Flicker noise measurement of HF quartz resonators

The frequency flicker of quartz resonators can be derived from the measurement of S/sub /spl phi//(f), i.e. the power spectrum density of phase fluctuations /spl phi/. Besides, the interferometric method turns out to be the best choice to measure the quartz resonator phase fluctuations because of its high sensitivity even in the low power conditions required for these devices. Combining these two ideas, we built an instrument suitable to measure the resonator frequency flicker floor and we measured the stability of some 10 MHz high performances resonators as a function of the dissipated power. The stability limit of our instrument, described in terms of Allan deviation /spl sigma//sub y/(/spl tau/), is of some 10/sup -14/.