Surface Acoustic Wave Vibration Sensors for Linear Electronic Warning Systems

The topic of the paper is analysis of feasibility of surface acoustic wave vibration sensors for linear electronic warning systems. In linear warning systems localisation of the object is realised by pointing out the sensors which detect vibrations caused by the object. The information sent out by the detector enables identification of the sensor and its state. The sensor contains surface acoustic wave delay line in four-terminal network. The delay line is formed at the surface of piezoelectric plate. The vibrations of the plate are caused by vibrations of the medium surrounding the sensor. The frequency of the input signal is equal to the working frequency of delay line. The phase of the output signal is shifted in comparison with the input signal. The frequency of the phase shift would be equal to the resonance frequency of the sensor plate. The change of the output signal amplitude would be proportional to the amplitude of plate vibrations. The measured amplitude and frequency of the output signal would be registered by simple electronic devices. The measurements give us knowledge which sensor vibrates and the intensity of these vibrations. Such sensors enable construction of the electronic warning system.