Interrogation of SAW - Resonator-Based Vibration Sensor by Low Cost SDR

A wireless vibration sensor based on surface acoustic wave (SAW) devices as the deformation sensitive elements is a prospective type of sensor for application in different fields of the industry due to the possibility of vibration monitoring in heated objects. The software defined radio (SDR) as a base of sensor interrogation unit is attractive due to the possibility of easily changing of the interrogation signal parameters, selection of the received signal processing method, and realization of complicated interrogation algorithms. In this paper the interrogation of SAW vibration sensor by a low cost SDR is described. An SDR control program for interrogation signal generation by one SDR unit together with the observation of generated signal and of the sensor response by another SDR unit, and a program for observation of vibration related deformation by this pair of SDRs were developed in a free software suite. The experimental interrogation unit was tested for vibration characterization in the frequncy range of about 0.5 - 2 kHz and with the interrogation distance up to 50 cm,