Exploration of 1/f noise origin using time measurements

Noise measurements of quartz crystal resonators have been done by using a passive phase noise measurement technique. The tested resonators have been fabricated with exactly the same process. The short-term stabilities of a large portion of these resonators are measured to be lower than 8E-14. However, rest of them shows much worse results around few 1E-12. We are consequently carrying investigations on the origin of these differences. In this paper, high speed measurements of the acoustic wave attenuation achieved on the best and worse resonators are presented. Acoustic damping due to nonlinear effects such as, interaction of the acoustic wave with crystal defects is a well-known phenomenon. Hence, we explore the possibility to extract a damping contribution with the same physical origin as 1/f noise, by studying what is left after subtraction of the classical viscoelastic exponential damping. Preliminary results are presented in this paper.