STUDY OF THE SENSITIVITY OF QUARTZ SURFAC E-ACOUSTIC-WAVE OSCILLATORSTO STRESS EFFECT AND THERMAL-GRADIENTS

Sensitivity of Rayleigh wave devices to static thermal and mechanical stress has been theoretically and experimentally investigated in order to point out the existence of quartz cuts with a low-sensitivity to t hese phenomena. Two families of singly rotated surface acoustic wave c uts in the vicinity of the crystallographic angles (phi = 0 degrees; t heta = -10 degrees; psi = 30 degrees) (TG cut) and (phi = 0 degrees; t heta = 41.8 degrees; psi = 48.2 degrees) (close to STC cut) exhibit a low sensitivity to static temperature effects and to symmetrical radia l in-plane compression, in a good agreement with theoretical models. M oreover, experimental investigations have shown that these cuts are le ss sensitive by an order of magnitude to dynamic thermal effects than the (ST, X) cut which is the present industry standard. Applications o f these devices to ultra-stable oscillators could improve their perfor mances when submitted to accelerations or to a severely perturbed ther mal environment.