RFID+: Spatially Controllable Identification of UHF RFIDs via Controlled Magnetic Fields

In the fast-paced landscape of UHF RFID technology, achieving precise spatial-selective identification is of critical importance in the logistics and retail domain. This work introduces RFID+, a magnetically-driven UHF RFID system that leverages the matching loops of commercial-off-the-shelf UHF RFID tags for efficient energy harvesting from tailored magnetic fields. The RFID+ delivers a level of spatial precision comparable to that of HF NFC systems, effectively mitigating issues of miss-reading and cross-reading. Our primary contributions reside in the development of a specialized multi-turn, capacitor-segmented coil antenna and an innovative fast inventory algorithm. The RFID+ seamlessly integrates traditional radiative coupling with the innovative magnetic coupling in UHF RFID systems, bolstering their overall performance and efficiency. Real-world pilot studies in warehouses and logistics settings reveal that RFID+ significantly diminishes the miss-reading rate from 22.9% down to a remarkable 1.06%, while entirely eliminating cross-reading challenges. Moreover, our RFID+ variant demonstrates better resilience against materials traditionally challenging for UHF RFID, such as water bottles and containers. These advancements make RFID+ exceedingly relevant for practical applications in logistical networks.