Metasurface Based WiFi Tag with High Angular Stability

This paper proposes a WiFi tag design with high angular stability that is passive and suitable for applications such as indoor localization, environmental sensing, and material identification within the WiFi frequency range, utilizing existing infrastructure. It offers advantages including low maintenance cost, simplicity, and accuracy. The tag integrates a metasurface and a retroreflector, demonstrating high angular stability and detectability at normal incidence. In preliminary experiments, the tag can at least operate effectively at a distance of 550 mm.