A Small-Divergence-Angle Orbital Angular Momentum Metasurface Antenna
Jianchun Xu,
Ke Bi,
Ru Zhang,
Yanan Hao,
Chuwen Lan,
Klaus D. McDonald-Maier,
Xiaojun Zhai,
Zidong Zhang,
Shanguo Huang
Affiliations
Jianchun Xu
State Key Laboratory of Information Photonics and Optical Communications, School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China
Ke Bi
State Key Laboratory of Information Photonics and Optical Communications, School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China; Beijing University of Posts and Telecommunications Research Institute, Shenzhen 518057, China
Ru Zhang
State Key Laboratory of Information Photonics and Optical Communications, School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China; Beijing Key Laboratory of Space-Ground Interconnection and Convergence, Beijing University of Posts and Telecommunications, Beijing 100876, China
Yanan Hao
State Key Laboratory of Information Photonics and Optical Communications, School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China
Chuwen Lan
State Key Laboratory of Information Photonics and Optical Communications, School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China
Klaus D. McDonald-Maier
School of Computer Science and Electronic Engineering, University of Essex, Colchester CO4 3SQ, UK
Xiaojun Zhai
School of Computer Science and Electronic Engineering, University of Essex, Colchester CO4 3SQ, UK
Zidong Zhang
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, China
Shanguo Huang
State Key Laboratory of Information Photonics and Optical Communications, School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, China
Electromagnetic waves carrying an orbital angular momentum (OAM) are of great interest. However, most OAM antennas present disadvantages such as a complicated structure, low efficiency, and large divergence angle, which prevents their practical applications. So far, there are few papers and research focuses on the problem of the divergence angle. Herein, a metasurface antenna is proposed to obtain the OAM beams with a small divergence angle. The circular arrangement and phase gradient were used to simplify the structure of the metasurface and obtain the small divergence angle, respectively. The proposed metasurface antenna presents a high transmission coefficient and effectively decreases the divergence angle of the OAM beam. All the theoretical analyses and derivation calculations were validated by both simulations and experiments. This compact structure paves the way to generate OAM beams with a small divergence angle.
