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We have investigated some improved ring-supported (r-s) resonators. These resonators show promise of providing high precision frequencies for a wide temperature range and static and dynamic forces encountered in the field. In this paper, we report the experimental results of the temperature and force effects for the improved ring-supported resonators. These resonators are ring-supported and made from bi-convex quartz and from concavo-convex quartz in a suitable contour form. The frequency-temperature characteristics of these resonators are measured over a wide temperature range, -196 C - +160 C. Fortunately, it is seen that the results of the improved r-s concavo-convex quartz show excellent frequency stability., This article is from the Proceedings of the Symposium on Frequency Control (36th Annual), 2-4 Jun 82, Philadelphia, PA., AD-A130 811, p513-516.

This invention relates to the field of piezoelectric resonators and more particularly to quartz crystal resonators that are highly insensitive to paraxial accelerations. Frequency perturbations are produced in thickness mode crystal resonators by acceleration-induced forces acting on the body of the resonator. These forces are distributed throughout the resonator volume and vary with the acceleration direction. For specific acceleration directions, the effect can be sharply reduced by changing the points of application of the mounting supports. When the acceleration direction is known in advance, positioning the resonator with respect to the direction minimizes the problem. In high shock and vibration environments, however, accelerations occur in arbitrary directions with ensuing large frequency shifts in the crystal resonance frequency. When the acceleration is arbitrarily oriented with respect to the resonator, no crystal cut or combination of mounting supports can by themselves produce cancellations of the frequency perturbations to the extent required.

A new family of stress compensated quartz resonators having cuts exhibiting an ultra-linear frequency vs. temperature characteristic. This family of resonators has an orientation defined with respect to the crystallographic axes by polar angles phi and theta, which angles lies on the locus where the second-order temperature coefficient of frequency is zero between the angles phi = 20 deg + or - 2 deg and theta = 20 deg + or - 5 deg, and in close proximity to the locus of zero coefficient of stress. In one preferred embodiment, the resonator comprises a plate whose angles of cut phi and theta are both substantially equal to 20 deg. In a second preferred embodiment an exact stress compensation is provided where phi is substantially equal to 20.8 deg and theta is substantially equal to 23.2 deg, an orientation where the locus of the zero coefficient of stress intersects the locus of the zero of the second-order temperature coefficient. (Author)

Quartz crystal resonators have been employed in a number of thermometer applications. We have recently discovered two new thermometric cuts; one exhibits a high degree of linearity over a wide temperature range; the other is located in the vicinity of the stress compensated locus. These doubly rotated cuts were found by calculations based on the thickness - vibration theory for ideal plates. This paper presents theoretical and experimental results concerning the frequency-temperature characteristics of these quartz resonators., This article is from the Proceedings of the Symposium on Frequency Control (36th Annual), 2-4 Jun 82, Philadelphia, PA., AD-A130 811, p290-296.