A High-Gain Transmitarray for Generating Dual-Mode OAM Beams
A High-Gain Transmitarray for Generating Dual-Mode OAM Beams
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DOI：
10.1109/access.2018.2875680
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发表时间：
2018-10
期刊：
影响因子：
3.9
通讯作者：
F. Qin;Steven Gao;Wenchi Cheng;Yi Liu;Hai-Lin Zhang;G. Wei
中科院分区：
文献类型：
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作者：
F. Qin;Steven Gao;Wenchi Cheng;Yi Liu;Hai-Lin Zhang;G. Wei
提出了一种新型的Ku波段发射阵列天线，该天线可以获得高增益并产生双模轨道角动量（OAM）波束。两个背靠背的宽带双极化微带天线被用作单元格，这是连接使用金属化过孔。通过改变两个正交极化中馈线的长度，可以获得完整的360°相位范围。由于两个正交偏振之间的高度隔离，可以通过分别调谐x偏振和y偏振中的相位分布来同时形成双模OAM光束。解释了用于产生OAM光束的方法。为了验证这一概念，一个原型进行0和+1模式OAM光束的设计，制造和测量。实验结果表明，0模和+1模OAM光束均能成功产生，且实验结果与模拟结果吻合较好。由于发射阵列的高方向性和聚焦效应，所提出的+1模OAM波束在长距离传输时具有稳定的性能。最大增益在0模和+1模OAM光束中分别达到26和20 dBi。同时，在+1模OAM光束中获得了±5°的窄发散角。与已有的OAM天线相比，该天线具有增益高、发散角窄、成本低、平面结构和可产生双模OAM波束等优点。
This paper proposes a novel transmitarray antenna which can achieve high gain and produce dual-mode orbital angular momentum (OAM) beams in Ku-band. Two back-to-back wideband dual-polarized microstrip antennas are employed as the unit cells, which are connected using metalized via holes. Full 360° phase ranges can be obtained by varying the length of feeding lines in two orthogonal polarizations. Due to high isolation between the two orthogonal polarizations, dual-mode OAM beams can be formed simultaneously by tuning phase distributions in x- and y-polarizations, respectively. The approach for generating OAM beams is explained. To verify this concept, one prototype carrying 0 and +1 mode OAM beams is designed, fabricated, and measured. Experimental results demonstrate that both 0 and +1 mode OAM beams can be generated successfully, and the measured results agree well with the simulated results. Because of high directivity and focusing effects of transmitarray, the proposed +1 mode OAM beam has stable performance at a long propagation distance. The maximum gain reaches 26 and 20 dBi in 0 and +1 mode OAM beams, respectively. Meanwhile, a narrow divergence angle of ±5° is obtained in +1 mode OAM beam. Compared with other OAM antennas reported, main advantages of the proposed antenna include high gain, narrow divergence angle, low cost, planar structure, and the capability of producing dual-mode OAM beams.