Electromagnetic characterisation of self-tuning UHF RFID tags for sensing application

Recently introduced self-tuning UHF RFID microchips offer interesting possibility for low-cost sensing. We have investigated the response of such a chip embedded into a meandered-dipole tag versus the interrogation modalities, the frequency and the variable boundary conditions. A simple impedance model has permitted to accurately reproduce the tag behaviour during the monitoring of the filling level of a box.