涡旋电磁波无线通信技术的研究进展  

Research Status of Vortex Electromagnetic Wave Wireless Communication Technologies

作　　者：赵林军[1,2] 张海林 刘乃安[2] ZHAO Linjun;ZHANG Hailin;LIU Naian(School of Physics and Telecommunication Engineeringg,Shaanxi University of Technology,Hanzhong 723000,China;School of Telecommunications of Engineering,Xidian University,Xi’an 710071,China)

机构地区：[1]陕西理工大学物电学院,汉中723000 [2]西安电子科技大学通信工程学院,西安710071

出　　处：《电子与信息学报》2021年第11期3075-3085,共11页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(61671347,61876143);陕西理工大学人才计划项目(SLGRC20200028)。

摘　　要：由电磁动力学可知,电磁波可携带与极化方式相关的自旋角动量(Spin Angular Momentum,SAM)和与坡印廷矢量运动方式相关的轨道角动量(Orbital Angular Momentum,OAM)。当OAM不为零时,电磁波的波前电场分布呈漩涡状且具有沿轴向传播的特性,人们形象地将这类电磁波称为涡旋电磁波。学界在平面电磁波场强数学模型的基础上引入了一个以OAM的拓扑荷(又称模态)为参数的傅里叶旋转因子描述涡旋电磁波的波前场,因此,涡旋电磁波波前具有与拓扑荷相关联的“极化”图案,利用不同模态的涡旋电磁波的极化图案可进一步提升无线通信系统信道容量。研究表明,在开放环境下由均匀圆阵列(Uniform Circular Array,UCA)阵列产生“平面”涡旋电磁波波束尽管可行,但要获得模态复用增益,需要探索基于复平面内单位圆周上分布的正交相位序列的涡旋电磁波波束产生与信息传输方法。文中也调研了无线射频领域OAM与MIMO体制相兼容的研究现状。It is known from electromagnetic momentum that electromagnetic waves can carry Spin Angular Momentum(SAM)related to polarization and Orbital Angular Momentum(OAM)related to the trajectory of the Poynting vector.When OAM is not zero,the wave-front electric field distribution of the electromagnetic wave is vortex-like and has the characteristic of propagating along the axial direction.Therefore,this electromagnetic wave is aptly named vortex electromagnetic wave.Based on the mathematical model of the plane electromagnetic wave field,the researchers introduce a Fourier factor that uses the topological charge(also called mode)of the OAM as a parameter to describe the field of the vortex electromagnetic wave.Therefore,the wave-front of the vortex electromagnetic wave with a“polarization”pattern associated with topological charge,the use of polarization patterns of vortex electromagnetic waves in different modes can further increase the spectrum effect of the wireless communication system.Studies show that although it is feasible to generate"planar"vortex electromagnetic wave beams from Uniform Circular Array(UCA)arrays in an open environment,to obtain modal multiplexing gain,and it is necessary to explore vortex electromagnetic wave beams based on orthogonal phase sequences distributed on a unit circle in the complex plane.At the same time,the paper also investigates the current research status of compatibility between OAM and Multiple Input Multiple Output(MIMO)systems in the field of radio frequency.

关 键 词：涡旋电磁波 涡旋电磁波MIMO 极化纹理 轨道角动量 模态正交分离 

分 类 号：TN92[电子电信—通信与信息系统]