A Program to Analyse the Origin of Noise in Ultra- Stable Quartz Crystal Resonators

Serge Galliou (1) , Fabrice Sthal (1) , Xavier Vacheret (1) , Rémi Brendel (1) , Patrice Salzenstein (1) , Enrico Rubiola (1) , Gilles Cibiel (2)

1 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)
2 CNES - Centre National d'Études Spatiales [Toulouse]

In the mid 90s the quartz crystal oscillator attained a stability in the upper 10–14 (flicker floor of the Allan deviation σy(τ), which occurs at τ =1..10 s). As a matter of fact, the highest stability was obtained with bulk-acoustic-wave quartz crystal resonators at 5 MHz and at 10 MHz. Since, the research for higher stability seems to be at a standstill, while space applications are more and more demanding. Recently, the analysis of a few premium-stability oscillators has shown that the oscillator frequency instability is due to the fluctuation of the resonator natural frequency, rather than to the noise of the sustaining amplifier via the Leeson effect. It is therefore natural to give attention to the measurement of the resonator fluctuations. The Centre National d'Etudes Spatiales (CNES) and FEMTO-ST Institute have started a research program on the origin of noise in 5 MHz and 10 MHz quartz crystal resonators. Several European manufacturers of high-stability resonators and oscillators participate. This article reports on the present status and on the future plans of this program. The first part consists in the analysis of the sensitivity of selected resonators to various externally-controlled parameters, like temperature, drive power, load impedance, series capacitance. The second part, planned, consists of listing the possible causes of noise, and of modeling their effects on frequency stability. Tests and measurements are mainly performed on an advanced phase noise measurement system, recently set up for this program. Of course, this program is a unique opportunity to test various batches of 5 MHz and 10 MHz resonators provided by the industrial partners.

Domaines: Instrumentations et Détecteurs [physics.ins-det]

Serge Galliou, Fabrice Sthal, Xavier Vacheret, Rémi Brendel, Patrice Salzenstein, et al.. A Program to Analyse the Origin of Noise in Ultra- Stable Quartz Crystal Resonators. IEEE Frequency Control Symposium & European Time and Frequency Forum, Jun 2007, Geneva, Switzerland. pp.1176-1181, ⟨10.1109/FREQ.2007.4319263⟩. ⟨hal-00154309⟩