EM design of a passive RFID-based device with sensing and reasoning capabilities

In the last years, the continuous demand for smart applications in the Internet of Things context is leading to the develop of novel and more complex UHF RFID tags with augmented capabilities. Novel tags offer additional functionalities besides identification by embedding sensors, actuators, and processing units. In this work a new kind of device, called SPARTACUS, is presented. While being completely passive, it conjugates identification, sensing, local computing, and actuation control and enables a proactive communication with any standard RFID reader. Thanks to an accurate electromagnetic design and exploiting polarization diversity of two antennas performing both energy harvesting and communication, SPARTACUS ensures compactness, energy-efficiency, and ease of use. The paper presents detailed design of the device, besides discussing system validation and performance evaluation.