An Efficient Multi-Beam Generation Method for Millimeter-Wave Reconfigurable Intelligent Surface: Simulation and Measurement
Shengguo Meng, Wankai Tang, Zhexuan Yu, Jinghe Wang, Jifeng Lan, Xin Su, Yifei Yuan, Xiao Li, Shi Jin, Qiang Cheng, Tie Jun Cui
Abstract
Reconfigurable intelligent surface (RIS) is a promising technology for controlling wireless signals. In particular, it has the potential to provide remarkable performance improvements for wireless links, which is especially appealing for millimeter-wave (mmWave) communications. With this purpose, a proper design of the RIS's reflection beam patterns is highly required. In this paper, a direct method is firstly introduced for multi-beam generations based on RIS. Then, equipped with the artificial bee colony (ABC) algorithm, an efficient multi-beam generation method is proposed to configure RIS for high-performance multi-beam patterns on top of the direct method as the initial design. Finally, by employing a fabricated mmWave RIS, we conduct numerical simulations and experimental measurements, and the measured results validate that the proposed method can obtain higher-quality RIS-based multi-beam patterns with an average 7.96 dB side-lobe level reduction, which may provide an efficient way to enhance the capacity of mmWave communications.