标题： 使用喇叭天线生成高纯度毫米波轨道角动量模式：理论与实现 显示英文标题

标题： Generation of High-Purity Millimeter-Wave Orbital Angular Momentum Modes Using Horn Antenna: Theory and Implementation

摘要： 具有螺旋相位前沿的扭曲电磁波被称为轨道角动量（OAM），最近已被用于量子信息、高速通信和雷达探测。在此背景下，从低频段到光领域，生成高纯度携带OAM的波具有重要意义和挑战性。在这里，提出了一种新颖的模式组合方法，以生成具有任意OAM指数的扭曲波。使用圆形喇叭天线的高阶模式生成具有相当高纯度的扭曲波。所提出的策略通过理论分析、数值模拟和实验进行了验证。设计、制造并测量了一个工作在毫米波频段的圆形喇叭天线。获得了OAM指数为l=+1和l=-1的两个扭曲波，其模式纯度高达87%。与其它OAM天线相比，此处提出的天线具有高天线增益（超过12 dBi）和宽的工作带宽（超过15%）。高模式纯度、高天线增益和宽的工作带宽使该天线适用于扭曲波的应用，不仅在微波和毫米波频段，而且在太赫兹频段。 显示英文摘要

摘要： Twisted electromagnetic waves, of which the helical phase front is called orbital angular momentum (OAM), have been recently explored for quantum information, high speed communication and radar detections. In this context, generation of high purity waves carrying OAM is of great significance and challenge from low frequency band to optical area. Here, a novel strategy of mode combination method is proposed to generate twisted waves with arbitrary order of OAM index. The higher order mode of a circular horn antenna is used to generate the twisted waves with quite high purity. The proposed strategy is verified with theoretical analysis, numerical simulation and experiments. A circular horn antenna operating at millimeter wave band is designed, fabricated, and measured. Two twisted waves with OAM index of l=+1 and l=-1 with a mode purity as high as 87% are obtained. Compared with the other OAM antennas, the antenna proposed here owns a high antenna gain (over 12 dBi) and wide operating bandwidth (over 15%). The high mode purity, high antenna gain and wide operating band make the antenna suitable for the twisted-wave applications, not only in the microwave and millimeter wave band, but also in the terahertz band.