Passive wireless temperature sensor for high temperature applications with conductive surrounding

This paper presents a passive wireless temperature sensor designed for temperatures up to 200°C and to work on and in carbon fiber or other conductive materials. Similarly to low frequency (LF) radio frequency identification (RFID) transponders, the measurement circuit is powered by an external reader device through its magnetic field using coupled coil antennas. The sensor signal is modulated by means of load modulation and transmitted to the reader where it is detected and analyzed. The sensor has been fabricated and its accuracy has been tested and compared with common wired sensors. The presented sensor enables measurements inside the fiber material during its curing inside an oven in replacement or amends of common wired sensors.