Detection, Localization, and Sensing of Millimeter-Wave Van Atta Array-Based Chipless RFID Tags for Emerging 6G Applications

The sixth-generation (6G) vision of a massively interconnected world positions chipless radio-frequency identification (RFID) as a key enabling technology for providing low-cost, battery-free object identification and localization. This paper presents a method and a prototype system for simultaneous reading and localization of prototype millimeter-wave (V-band) Van Atta array-based frequency coded chipless RFID tags using a Vector Network Analyzer. Successful reading and localization in the anechoic and reflective environment is presented. The employed tags can be localized with a mean angular error of 1 degree and a mean range determination error of about 1.3 cm at distances up to 4 m. The system’s robustness is further confirmed through successful operation against challenging backgrounds, including large metallic surfaces. A proof-of-concept 4-bit frequency-coded ID is reliably decoded and positioned, demonstrating the system’s capabilities. To the best of the authors’ knowledge, this is the first work to present a practical implementation and validation of simultaneous localization and identification for millimeter-wave chipless and batteryless RFID tags, representing a step towards realizing joint localization and sensing systems in future 6G applications. The proposed solution also offers the highest bit encoding capacity and the longest read-out distance among all millimeter-wave (mmWave) solutions known to the authors.