Abstract: The invention is a method and apparatus for improving the aging, pressure sensitivity, and acceleration sensitivity of crystal resonators. In one embodiment the invention includes a coplanar two-dimensional compliant mounting structure, wherein the symmetry and compliance of the planar mounting structure reduces the effects of residual static stresses and dynamic vibratory stresses on the vibration sensitivity performance of a crystal resonator. The structural elements include compliance loops that provide relief from the effects associated with manufacturing, thermal and vibration stresses.

Abstract: The invention is a method and apparatus for improving the aging, pressure sensitivity, and acceleration sensitivity of crystal resonators. In one embodiment the invention includes a coplanar two-dimensional compliant mounting structure, wherein the symmetry and compliance of the planar mounting structure reduces the effects of residual static stresses and dynamic vibratory stresses on the vibration sensitivity performance of a crystal resonator. The structural elements include compliance loops that provide relief from the effects associated with manufacturing, thermal and vibration stresses.

Abstract: A temperature compensated mounting structure, such that the stress applied to the resonator element by the mounting is minimized over a wide range of temperatures. This compensation significantly reduces or eliminates residual stresses from earlier process stages, such as cement curing, as well as stresses induced by ambient temperature changes. The entire structure is designed to be stress-free by the selection of materials and the dimensions of the elements. The geometry of the structure and the choice of materials are selected based on their linear and higher order expansion coefficients so as to minimize the forces between the resonator element and the mount resulting from temperature changes.

Abstract: The temperature of a quartz crystal oscillator is determined by comparison of a pair of inharmonically related overtone oxcillations of the same vibrational type, e.g. a thickness shear mode, and of the same overtone order. The use of inharmonically related signals relaxes the contraints on crystal design. The technique may be employed in a crystal controlled frequency synthesizer to provide a feedback signal for maintaining constant output frequency.