Passive UHF RFID antennas for sensing applications: Principles, methods, and classifcations

TLDR

UHF passive RFID is evolving from simple labeling to pervasive sensing, enabling remote monitoring of objects’ physical properties throughout their life cycle and requiring antenna designs that balance communication performance with sensitivity to changing boundary conditions. This paper reviews the state of the art of tag‑as‑sensor systems, aiming to formalize measurement indicators and the trade‑off between communication and sensing to provide a knowledge base for emerging sensing applications. The review synthesizes existing approaches, formalizing measurement indicators and the communication‑sensing trade‑off to guide the design of tag‑as‑sensor antennas.

Abstract

UHF passive radio-frequency identification technology is rapidly evolving from simple labeling of things to wireless pervasive sensing. A remarkable number of scientific papers demonstrate that objects in principle can have their physical properties be remotely tracked and monitored all along their life cycle. The key background is a new paradigm of antenna design that merges together the conventional communication issues with more-specific requirements about sensitivity to time-varying boundary conditions. This paper presents a unified review of the state of the art of the tag-as-sensor problem. Particular care is taken to formalize the measurement indicators and the communication and sensing tradeoff, with the purpose to provide a first knowledge base for facing a large variety of emerging sensing applications.