Electromagnetic Modeling and Correction of RFID Temperature Sensors under Random Wireless Interrogation

UHF-Radio frequency identification (RFID) technology applied for sensing procedures is nowadays a well-established trend. However, the response of the Integrated Circuit (IC) transponder is sensitive to the strength of the interrogating power that may produce non linear effects and alterations in measurement evaluation. Starting from experimental measurements on tags with integrated temperature sensor, this work demonstrates that the error affecting the measurement is, in some conditions, predictable and hence correctable. An electromagnetic-thermal correction model is proposed and validated, with the final aim to overcome the instabilities due to the chip non-linearity.