A Wireless, Passive ID Tag and Temperature Sensor for a Wide Range of Operation

Surface acoustic wave (SAW) devices are since long known for their wireless sensing capabilities in harsh environment. While the mainstream of the investigations was so far dedicated to room temperature or high temperature applications, we have demonstrated the employment of SAW based sensors at temperatures down to -200°C. We constructed SAW sensors for cryogenic temperatures that are based on reflective delay lines and feature a unique identification number. We tested them in a dedicated setup during cooling, both wired and wireless. As results figures for the reading range, the temperature resolution and reproducibility were derived. The devices show a good and reliable performance in an operating range from -200°C to 200°C.