基于微波光子学的射频涡旋波接收技术研究

Orbital angular momentum Mode division multiplexing (OAM-MDM) in radio frequency proposes a new dimension of multiplexing way for wireless communication systems. It is one of the most promising methods for increasing the capacity of wireless communication systems, also a frontier researching topic in the field of international optical communication systems. The flexible and accurate reception of votex Orbital angular momentum Mode division multiplexing (OAM-MDM) in radio frequency proposes a new dimension of multiplexing way for wireless communication systems. It is one of the most promising methods for increasing the capacity of wireless communication systems, also a frontier researching topic in the field of international optical communication systems. The flexible and accurate reception, mode measurement and frequency detection of vortex beams are the essential parts and technical difficulties of OAM-MDM wireless communication systems, which need to be solved firstly. Therefore, this project focuses on the requirements and principal problems of OAM-MDM wireless communication systems, researching on, “mechanism and methods of flexible and accurate reception of any radio frequency OAM mode based on microwave photons phase-shift technique”, “the mechanism and measurement methods of arbitrary radio frequency OAM mode based on phased-antenna array”， and “the mechanism of subtle frequency deviation measurement of radio frequency OAM mode” .Large bandwith , multi-mode, and low complexity methods of mode reception and mode conversion are to be proposed.Through theoretical research and experimental verification, we will make innovation in “radio frequency vortex electromagnetic waves receiver based on microwave photonics”. The achievements of this project will provide important guidance for the development of OAM-MDM wireless communication systems in China, and lay solid foundations for the next generation of ultra-high speed, ultra-high capacity wireless communication systems.

射频信号的轨道角动量模式复用在通信系统中增加了一个新的复用方式，是大幅增加信道容量的最有前景的方法之一，已成为当前国内外通信领域的前沿与热点研究问题。其中，灵活精准的射频涡旋波（具有轨道角动量的射频波束）接收、模式识别和频移检测是轨道角动量模分复用无线通信系统的基本组成部分和关键问题。在当前涡旋波模式接收和处理方法并不成熟的情况下，本课题面向未来轨道角动量模分复用无线通信系统的需求和基本问题，探索大带宽、多模式的轨道角动量复用接收技术，对基于微波光子技术的任意射频涡旋模式接收解调机理、基于环形相控天线阵列任意射频涡旋模式识别方法及射频涡旋信号微小频率变化检测机制进行研究，通过理论研究和实验验证，在“基于微波光子技术的射频涡旋电磁波的接收”方面形成创新。本项目的研究成果将为我国轨道角动量复用无线通信系统的发展提供重要参考，为下一代超高速率、超大容量的无线通信系统的发展提供有力支撑。

作为基于轨道角动量模分复用（OAM-MDM）的无线通信系统的关键组成部分，射频涡旋波（RF-OAM）的复用接收端与发射端相同，吸引着世界各地的学者进行研究。本项目的研究内容选择并重点研究基于微波光子学信息处理的RF-OAM的接收方式，研究集中在光控RF-OAM多模式接收、模式识别、频移检测等亟待解决的技术问题，具有较好的应用导向性和创新性，预计5-10年内应用在微波光子雷达领域或无线通信领域中。.重点进展及指标完成情况如下，第一，在“任意射频OAM模式的接收机理与实现”方面提出高精度超宽带色散免疫相移机理，其一，提出双边带色散免疫移相方案，实现19.4 km光纤传输后在14-24 GHz的范围内宽带移相；其二，提出边带异信号相移方案，实现光控双模式射频涡旋波生成及方向控制，进而实现了RF-OAM的二维扫描功能，并成功接收了2个RF-OAM波束。完成指标：光载波频率为10-24GHz及接收轨道角动量模式数不少于4。第二，在“准确识别、区分接收信号中各个RF-OAM模式”方面形成两种识别评价方法。其一，提出了一种叠加OAM态纯度测量方法，实现自由空间涡旋电磁波叠加态纯度的测量。其二，提出了一种环形相位梯度法实现双重叠加态射频涡旋测量方法。完成指标：多重轨道角动量模式检测能力不少于2个模式。第三，在“RF-OAM模式微小频偏的探测”方面提出相位时间累计法，实现测量由为多普勒效应引起得微小频移。实验转速为50π/s, 测得频率为24.83Hz，频率误差为0.63%，实现指标：涡旋电磁波微小频移检测精度误差不超过1%。.在课题涉及的关键研究领域，发表SCI检索论文14篇，EI检索论文9篇。在Optics Letters，Optics Express等中科院JCR分区2区期刊上发表论文共7篇，其中，负责人为第一作者论文2篇（1篇为ESI高被引论文），负责人为通讯作者论文3篇。ACP2017、ICOCN2017，OGC2019会议邀请报告3人次。申请相关国家发明专利7项，已授权2项。培养博士6人，已毕业2人。.项目组超额完成了既定的预期目标。