Low cost thin film based surface acoustic wave vibration sensors for vibrational gyroscope

M. D. J. Potter, P. B. Kirby, M.Y. Lim, V. A. Kalinin, A. Lonsdale.

Proc. of 2002 IEEE Int. Frequency Control Symposium. New Orleans, USA, May 29-31, pp. 220-224.

Abstract

We report on development of thin film polycrystalline zinc oxide based surface acoustic wave (SAW) resonators for use as vibration sensors on a novel low cost vibrating gyroscope structure intended for use in a GPS-INS automotive navigation system. Piezoelectric growth conditions and layer configurations are optimised to produce resonators with high Q factor (>4000) required to detect kHz frequency strains in a macroscopic (3 cm diameter) vibrating structure. The system is ultimately intended to use contact free capacitive coupling schemes to the sensor for primary and secondary mode detection.

Initial strain sensitivity measurements of the SAW resonators have been performed, revealing a practical strain sensitivity of approximately 0.7845 kHz/microstrain.