Influence of acceleration on surface acoustic wave oscillators

The influence of acceleration on oscillators using a delay line or a resonator with surface acoustic waves was studied in the 0 - 30 g range. The surface wave oscillators were installed on a variable speed rotating arm. The piezoelectric substrates used were in quartz of ST and Y cut. Several directions of acceleration were experimented. The frequency shift due to acceleration is as a first approximation, a linear function of the acceleration magnitude. With a surface wave resonator made of two transducers placed in a cavity defined by two periodic reflecting networks, the maximum sensitivity is 48 Hz/g at 124 MHz for an acceleration direction to the propagation surface. Results show that the acoustic surface wave oscillators, in their present form, are more sensitive to acceleration than the volume wave oscillators. The ratio of relative sensitivity increase is of the order of 100.