Design and characterisation of a combined pressure, temperature, ID sensor for harsh environment

A combined pressure, temperature sensor with RFID functionality and wireless readout has been developed. The concept is based on a delay line on YZ-cut Lithiumniobate, which allows for a wireless interrogation in the 2.4 GHz ISM band. The sensor exhibits good sensitivity and linearity to pressure, but also a significant temperature dependence of pressure sensitivity. Due to mismatch of thermal expansion factors the sensor has a small offset drift with temperature. Both effects can be corrected using the inherent temperature information of the sensor. The sensor has been characterized from 20 °C to 180 °C. The measured pressure sensitivity is 5.3 rad/bar at 20 °C and 4.2 rad/bar at 180 °C. The sensor is intended for applications in the food and pharmaceutical industry.