Thermal sensitivity of transverse waves on thin quartz plates

Resonator-like devices have been built on AT-cut and Z-cut quartz plates 140 microns thick. The operating frequency of these devices was in the frequency range 90-150 MHz. The thermal sensitivity has been measured by applying quasi-static thermal cycles to an oscillator using these devices as a resonator. Since many transverse modes can propagate on the plates, the different modes have been tested for each device. Temperature compensation has been found experimentally in an extended frequency range for the AT-cut device, with turnover temperature varying from 30°C to 0°C. Extremely high sensitivity has been found for the first mode of the Z-cut device (higher than 65 ppm/°C) but also higher order modes were found to be temperature compensated. To explain these results, a model has been developed based on the Tiersten-Sinha perturbation method (1979) and a theoretical model of unperturbed propagation