A Study of Four-Switch Cross-Shaped RIS and A Novel Design Example

TL;DR

This paper analyzes a four-switch cross-shaped RIS structure, summarizes existing designs, and introduces a novel RIS that achieves ultra-wideband and narrowband functions with beam scanning, verified through simulations.

Contribution

It provides a detailed analysis of the four-switch cross-shaped RIS and proposes a new design enabling multi-band and beam scanning functionalities.

Findings

Achieves 10.5-19.8 GHz ultra-wideband coverage.

Realizes 2-bit phase quantization around 18.12 GHz.

Enables 60° two-dimensional beam scanning.

Abstract

This paper analyzes the working principle of four-switch cross-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 also points out several RIS solutions that have not been designed using this structure. Finally, based on this four-switch cross-shaped structure, this paper proposes a novel RIS design example that can realize the function switching of 1-bit ultra-wideband (UWB) and 2-bit narrowband, and conducts simulation verification. The simulation results show that by optimizing the element structure and controlling the states of the four switches, the 1-bit ultra-wideband function can achieve a frequency band coverage of 10.5GHz-19.8GHz and a 2-bit phase quantization function around 18.12GHz. At the same time, it can realize 60{\deg} two-dimensional beam scanning function. We call this novel design "bit reconfigurable metasurface".