Enhancing Link Performance in Low-altitude Intelligent Networking Using Spherical-cap Reconfigurable Intelligent Surfaces (ScRIS)

This paper investigates a method based on Spherical-cap Reconfigurable Intelligent Surfaces (ScRIS) to enhance link performance in low-altitude communications. In low-altitude communication environments, traditional planar RIS faces challenges such as instability in reflected beam direction due to attitude changes. In contrast, the ScRIS leverages its curved surface structure to provide superior angular tolerance and omnidirectional coverage. By designing different encoding schemes (alternating, checkerboard, and random), this study explores their impact on communication link performance, focusing primarily on field uniformity, the Lowest Usable Frequency (LUF), link coverage, and link robustness. Simulation and experimental results demonstrate that ScRIS significantly improves coverage in low-frequency bands, reduces communication blind spots, and enhances link stability, making it particularly suitable for dynamic low-altitude communication environments, such as drone relay communications. This research offers a novel and effective link enhancement solution for low-altitude intelligent networking (LAIN), with broad application prospects.