A 16 × 16 Array Composed of 4 × 4 Fully Scalable Reconfigurable Intelligent Surfaces (RIS) for 2.4 GHz Wi-Fi Using RFID Distributed Control

作者：Saeid Alamdar, Sai-Wang Tam, Sahar Bagherkhani, Franco De Flaviis, Ziru Chen, Daniel Poehl, Mohammad Towliat, Rui Cao, Jeremy Baxter, June Sun, Aphia Ishimwe, Franz Amtmann, Peter Thueringer · 发表于：IEEE Transactions on Microwave Theory and Techniques · 年份：2025 · DOI：10.1109/tmtt.2025.3547686 · 被引用次数：9 · 研究领域：Advanced Antenna and Metasurface Technologies、Advanced Wireless Communication Technologies

This article proposes a scalable reconfigurable intelligent surface (RIS) that utilizes distributed wireless control for 2.4 GHz Wi-Fi systems, rather than centralized control, enabling it to scale to arbitrarily large surfaces. The RIS is composed of tiles, each containing$4 \times 4$unit cells. To control the RIS elements in each tile, we integrated a single radio frequency identification (RFID) antenna operating at a center frequency of 915 MHz. The RIS elements in each tile are connected to distinct delay lines using a single-pole four-throw (SP4T) RF switch configuration. This configuration allows phase manipulation of the reflected wave at 0°, 90°, 180°, and 270° round-trip phase shifts for each element. With this distributed control scheme, we achieve an ultralow-power, scalable RIS architecture that offers enhanced flexibility and adaptability. For verification, the bistatic radar cross section (RCS) of an$8 \times 8$-element is measured and compared with the simulation results, showing good agreement between the simulation and measurement. Furthermore, a$16 \times 16$-element RIS prototype, with a total size of$1 \times 1$m, is fabricated, and an experimental setup for realistic throughput (TP) measurement in typical office space and laboratory for both line of sight (LOS) and non-line of sight (NLOS) between receiver access point (AP) and transmitter AP using an actual Wi-Fi AP for different modulation coding scheme (MCS) index is measured and compared. The dc power...