Surface Acoustic Wave (SAW) Vibration Sensors

Sensors

Jerzy Filipiak²  Lech Solarz¹ 

[1] Department of Civil Engineering, Military University of Technology, 2 Kaliskiego Str., 00-908 Warsaw, Poland;Institute of Electronic and Control Systems, Technical University of Czestochowa, 17 A.K. Str., 42-200 Częstochowa, Poland; E-Mails:

关键词: surface acoustic waves;    vibration sensor;    delay line;    mechanical vibration;    electronic warning system;   

DOI  :  10.3390/s111211809

来源: mdpi

【 摘 要 】

In the paper a feasibility study on the use of surface acoustic wave (SAW) vibration sensors for electronic warning systems is presented. The system is assembled from concatenated SAW vibration sensors based on a SAW delay line manufactured on a surface of a piezoelectric plate. Vibrations of the plate are transformed into electric signals that allow identification of the sensor and localization of a threat. The theoretical study of sensor vibrations leads us to the simple isotropic model with one degree of freedom. This model allowed an explicit description of the sensor plate movement and identification of the vibrating sensor. Analysis of frequency response of the ST-cut quartz sensor plate and a damping speed of its impulse response has been conducted. The analysis above was the basis to determine the ranges of parameters for vibrating plates to be useful in electronic warning systems. Generally, operation of electronic warning systems with SAW vibration sensors is based on the analysis of signal phase changes at the working frequency of delay line after being transmitted via two circuits of concatenated four-terminal networks. Frequencies of phase changes are equal to resonance frequencies of vibrating plates of sensors. The amplitude of these phase changes is proportional to the amplitude of vibrations of a sensor plate. Both pieces of information may be sent and recorded jointly by a simple electrical unit.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.