Enhanced sensitivity of a surface acoustic wave based accelerometer

Abstract

This paper developed a surface acoustic wave (SAW) based accelerometer, it was composed of a flexible ST-X quartz cantilever beam with a relatively substantial proof mass at the undamped end, a pattern of two-port SAW resonator deposited directly on surface of the beam adjacent to the clamped end for maximum strain sensitivity, and a SAW resonator affixed on the metal package base for temperature compensation. The optimal dimensions of the cantilever beam were determined theoretically. Acceleration directed to the proof mass flex the cantilever, inducing relative changes in the acoustic propagation characteristics of the SAW traveling along the beams. The frequency signal from the differential oscillation structure utilizing the SAW resonators as the feedback element is used to characterize the applied acceleration. The sensor performance towards applied acceleration was evaluated by using the precise vibration table. High sensitivity, low detection limit and good linearity were observed in the acceleration experiments.