This paper proposes a new method of realizing multimode OAM beams with almost the same divergence angles. The theoretical relationship between the divergence angle of the OAM beam and its radiation source is presented, and the radiation source distributions for various mode OAM beams with the same divergence angle range are discussed. In order to verify this method, an eight-mode OAM antenna constructed by a bifocal parabolic reflector and dual OAM feeds is designed and simulated. The simulation results show that the divergence angle ranges of 3 dB beamwidth for OAM modes are , the divergence angles corresponding to the maximum beam directions are , respectively, and the maximum difference is within .

中文翻译：

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具有几乎相同发散角的多模OAM光束的实现

本文提出了一种实现几乎相同的发散角的多模OAM光束的新方法。给出了OAM光束发散角与其辐射源之间的理论关系，并讨论了相同发散角范围内各种模式OAM光束的辐射源分布。为了验证该方法，设计并仿真了由双焦点抛物面反射器和双OAM馈源构成的八模OAM天线。仿真结果表明，OAM模式的波束宽度发散角范围为3 dB 是 ，对应于最大光束方向的发散角为，最大差异在内。