基于2 bit超表面的单阶谐波波束扫描  

Single-order Harmonic Beam Scanning Based on 2 bit Metasurface

作　　者：符道临 于瑞涛 胡源 刘曦 熊伟 FU Daolin;YU Ruitao;HU Yuan;LIU Xi;XIONG Wei(Jiangsu Cyberspace Science and Technology Co.,Ltd.,Nanjing 211113,China;Hangzhou Qiantang Advanced Institute of Information,Hangzhou 310018,China;School of Electronic Engineering,Xidian University,Xi an 710071,China)

机构地区：[1]江苏赛博空间科学技术有限公司,江苏南京211113 [2]杭州市钱塘区信息高等研究院,浙江杭州310018 [3]西安电子科技大学电子工程学院,陕西西安710071

出　　处：《无线电通信技术》2024年第2期392-398,共7页Radio Communications Technology

摘　　要：波束扫描是一种广泛应用于无线通信、雷达、卫星通信和其他相关领域的技术,它允许无线信号或射线束在空间中定向、聚焦。近年提出的智能超表面时空编码方式拓展了超表面在物理维度上的自由度,使得其可以在单音波激励下完成多个频点的波束扫描,但仍然面临着增益低、波束副瓣大等一系列问题。针对这些问题,提出了一种基于超表面的谐波波束扫描方法。设计并加工了一种在E面可以达到斜入射60°的角度不敏感2 bit超表面单元并组建32×32阵列。针对单元谐波状态做出精确的3 bit相位量化。通过针对不同的初始参考相位,使用多目标遗传算法进行优化,将正一阶谐波的波束副瓣压低在了-15 dB水平,完成了时空编码超表面在E面60°波束扫描,为未来在超表面时空编码谐波波束赋形提供了充分有力的方案。Beam scanning is a technology widely used in wireless communication,radar,satellite communication and other fields.It allows wireless signals or ray beams to be oriented,focused in space.The smart metasurface space-time coding method proposed in recent years has expanded the degrees of freedom of metasurfaces in physical dimension,so that it can complete beam scanning at multiple frequencies under single-tone excitation.Howerver it still faces a series of problems such as low gain and large beam sidelobe.To solve this problem,a metasurface-based harmonic beam scanning method is proposed in this paper.Firstly,a 2 bit matesurface unit which can achieve 60°oblique incidence angle in the E plane is designed and processed,and a 32×32 array is formed.Secondly,an accurate 3 bit phase quantization is made for the unit harmonic state.Finally,by using the multi-objective genetic algorithm to optimize the different initial reference phases,the beam sidelobe of the positive first-order harmonics is reduced to the level of-15 dB,and the 60°beam scanning of the space-time coding metasurface on the E-plane is completed.This scheme provides a sufficient and powerful scheme for future time-space coding harmonic beamforming on metasurface.

关 键 词：超表面 时空编码 波束扫描 副瓣压低 多目标遗传算法 

分 类 号：TN919.23[电子电信—通信与信息系统]