Abstract
The implementation and performance of a surface acoustic wave (SAW)-based acceleration sensor is described. The sensor was composed of a flexible ST-X quartz cantilever beam with a relatively substantial proof mass at the undamped end, a pattern of a two-port SAW resonator deposited directly on the 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 acceleration was directed to the proof mass flex of 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 varies as a function of acceleration. The sensor response mechanism was analyzed theoretically, with the aim of determining the optimized dimension of the cantilever beam. The coupling of modes (COM) model was used to simulate the synchronous SAW resonator prior to fabrication. The oscillator frequency stability was improved using the phase modulation approach; the obtained typical short-term frequency stability ranged up to 1 Hz s−1. The performance of the developed acceleration sensor was evaluated using the precise vibration table and was also evaluated in comparison to the theoretical calculation. A high frequency sensitivity of 29.7 kHz g−1, good linearity and a lower detection limit (∼1 × 10−4 g) were achieved in the measured results.
Highlights
As the core component in the inertial measurement system, the acceleration sensor is used to measure the motion status of the object utilizing its inertial properties
Among a wide variety of acceleration sensors, the surface acoustic wave (SAW)-based acceleration sensor has gained increasing attraction for its inertial application because it exhibits some unique properties as a simple structure that is convenient to manufacturer with no auxiliary equipment; it is low cost, has good impact resistance, offers a stable and reliable performance and has high sensitivity [1]
The sensor was composed of a flexible ST-X quartz cantilever beam with a relatively substantial proof mass at the undamped end, a pattern of a two-port SAW resonator with an operating frequency of 300 MHz deposited directly on the 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
Summary
As the core component in the inertial measurement system, the acceleration sensor is used to measure the motion status of the object utilizing its inertial properties. The cantilever beam structure incorporating a SAW delay line pattern and the attached proof mass were advised for small vibration detection [9,10]; some theoretical analysis is performed on the dimension consideration of the pre-stressed cantilever beam. This provides a good starting point for the optimal design on the SAW accelerometer with a cantilever beam, In this paper, a SAW acceleration sensor incorporating a ST-X quartz cantilever beam was developed, which utilizes a differential resonator-oscillator structure, as shown in figure 1. A lower detection limit and excellent linearity were achieved experimentally
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
