本项目提出一种新的携带电磁轨道角动量波束的存在形式——平面螺旋轨道角动量电磁波，该电磁波沿径向方向传播，相位呈螺线分布，其相位奇点在中心天线位置，可解决远场暗区问题，而且不同拓朴荷值的平面螺旋轨道角动量波束可复用沿同方向传播。因此，平面螺旋轨道角动量波更符合射频波段的应用实际，其独特的波束特性在定位、测速、成像等电磁感知领域具有很大的潜在应用。本项目研究平面螺旋轨道角动量电磁波的基本特性和基于环形谐振腔缝隙行波天线的波束形成，并探索其在射频波段的应用，发展电磁感知的新概念、新原理和新技术。项目重点围绕平面螺旋轨道角动量电磁波，以环形行波天线为切入点，理论分析、技术实现和应用探索相结合，着力解决一些关键理论与技术问题。项目工作将为电磁轨道角动量研究提供了一个新的思维，以期充分利用轨道角动量这一尚未开发的电磁波参数资源，为未来射频波段电磁轨道角动量的应用提供基本原理和基础技术储备。

A new form of the orbital angular momentum (OAM) carried electromagnetic wave termed as plane spiral OAM electromagnetic wave, is proposed for the first time in this project. This electromagnetic wave possesses the fundamental character of the OAM carried waves, i.e. a spiral phase distribution, yet transmits along the radial direction. Hence the singularity of this wave is the radiated source itself, which can be used to solve the wide “dark zone” around the amplitude null when it transmits. Besides, different OAM mode plane spiral OAM electromagnetic waves can be easily multiplexed as no divergence exists. It is anticipated that these unique wave-beam characteristics will afford many potential applications in the field of electromagnetic sensing, such orientation, velocity measurement and imaging. In this project, the fundamental electromagnetic properties of the plane spiral OAM wave, the beam forming schemes based on the circular resonant slot antenna and its new applications in radio wave frequency are comprehensively studied. The key theory and new technologies concerning the electromagnetic OAM field will be effectively discussed based on the combinations of theory analysis, technology realizations and application explorations. The work in this project will offer a new field of vision for the research of electromagnetic OAM, and the expected results will provide the fundamental principle and technical support for the applications of the future OAM.