Passive Harmonic Transponders With RFID Capabilities: Common Challenges and Techniques

This paper provides a comprehensive analysis of recent advancements and ongoing challenges in passive harmonic RFID systems that take advantage of nonlinear operation to enable tracking, sensing, and monitoring in environments where conventional RFID systems fail. The study begins with a detailed review of the literature that highlights key trends and developments in harmonic RFID technology. Then it focusses on chipless harmonic RFID tags that are cost-effective, require no power supply, and operate through nonlinear backscattering, emphasising the main design challenges and limitations. The work further explores methodologies for enabling identification and data transmission in these systems, covering techniques used in tags designed for detection and tracking applications, as well as those meant to function as sensors. Finally, the paper suggests future research directions, emphasising the need for innovations in hybrid system designs, signal processing, and standardisation to improve the scalability and reliability of harmonic RFID systems.