In this article, a low‐profile and high‐gain multi‐beam antenna is proposed. The antenna consists of a cylindrical Luneburg lens based planar beamforming network, a folded double‐layer guided‐wave structure, and a leaky wave antenna (LWA) array. All the three parts are manufactured by 3D printing technology. The lens is realized by an n‐shaped gradual thickness unit to realize the refractive index variation of Luneburg lens in a parallel plate waveguide. The lens and the LWA array are folded into a double‐layer guided wave structure, which transforms the planar wave from the flat Luneburg lens to the LWA array to realize the antenna miniaturization. The antenna is excited by a radially placed microstrip antenna array at the focal plane of the lens. The proposed antenna has seven beams with minimum −2.5 dB crossover level, and the scanning range is ±29°. The broadside gain is 19.8 dB, and the gain variation in scan range is 2.7 dB. The proposed antenna is fabricated and tested, and the measured results agree well with the simulated ones. Due to the advantages including low‐profile, high aperture efficiency, high radiation efficiency, and low cost, the proposed design can find its applications in multi‐beam radar and communication systems.

中文翻译：

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基于3D打印柱面Luneburg透镜的低调高增益多波束天线

本文提出了一种低轮廓，高增益的多波束天线。天线由基于圆柱形Luneburg透镜的平面波束形成网络，折叠式双层导波结构和漏波天线（LWA）阵列组成。所有这三个部分都是通过3D打印技术制造的。透镜由n形渐变厚度单元实现，以实现Luneburg透镜在平行板波导中的折射率变化。透镜和LWA阵列折叠成双层导波结构，将平面波从平面Luneburg透镜转换为LWA阵列，以实现天线的小型化。天线由位于透镜焦平面的放射状微带天线阵列激发。拟议的天线具有七个波束，最小交叠电平为-2.5 dB 扫描范围为±29°。宽边增益为19.8 dB，扫描范围内的增益变化为2.7 dB。所提出的天线已经过制造和测试，测量结果与仿真结果吻合良好。由于具有低轮廓，高孔径效率，高辐射效率和低成本等优点，因此该设计可以在多波束雷达和通信系统中找到其应用。