Permittivity Passive RFID Sensor for Non-Cooperating Objects

This paper proposes a new paradigm of passive sensor radiofrequency identification devices for applications in the context of wireless sensor networks. The new tags family works in the UHF band and it is able to detect the value or the change of a tagged body´s feature without using any specific sensor. The system is provided with multiple chips placed on a cluster of antennas or onto a single multi-port antenna, and exploits the natural mismatching of an antenna´s input impedance with respect to a change of the target where it is placed.