X-RIS: A Study of the Principles and Applications of X-Shaped RIS

This paper analyzes the working principle of X-Shaped reconfigurable intelligent surface (RIS) in detail and reveals the different types of RIS that can be designed based on this structure. Combined with the design examples using this structure in the currently published articles, this paper summarizes and organizes them, and finally, based on this X-Shaped structure, this paper explores some other possible designs, which reflects the potential of the design versatility of the X-RIS structure.