Fast calibration of wireless and passive temperature sensors based on SAW resonators

The passive wireless surface acoustic wave (SAW) resonant sensors are suitable for the applications under harsh environments. A new calibration method has been proposed for passive wireless temperature sensors based on SAW resonators. It requires individual calibration of the sensors at the production stage only at three temperature points. This approach greatly simplifies calibration and reduces its cost in the case of high volume manufacturing. Analysis of calibration statistics has shown that the total measurement errors achieved in this case are very close to those obtained in the case of the individual sensor calibration in several temperature points over the entire operating temperature range. The idea of the method is to reduce the number of the temperature calibration points to simplify calibration.