Orientation Detection Using Passive UHF RFID Technology [Education Column]

A simple, compact, rechargeable handheld radio-frequency identification (RFID) reader was designed to detect the orientation of tagged objects. The system uses a linearly polarized reader antenna and the orientation sensor of the mobile device to identify the orientation of the tag. The system works in the ultra-high-frequency (UHF) RFID band. Detailed testing was done in different surroundings with various materials and tags. The system was able to correctly identify the orientation in several cases with an average angular error of less than 10°. This system can also be used to demonstrate the concept of polarization.