This letter presents a double-layer 45° linearly polarized (LP) wideband and highly efficient transmitarray antenna (TA). The proposed element is composed of two multi-resonant dipoles and four metal vias. The dipoles are placed on the diagonal of the unit cell and printed on both sides of the dielectric substrate. The metal vias which penetrate the substrate and connect the upper and lower dipoles are used to improve the transmission efficiency and obtain the large phase shift range of the proposed element. The proposed element realizes a full 360° phase shift range with a smooth slope in the band, and the magnitude loss is less than 1.5 dB at 20 GHz. The proposed TA is designed, manufactured, and measured. The measurement and simulation results are consistent. Measurement results indicate that the proposed TA has a maximum gain of 26.9 dBi at 20 GHz and an aperture efficiency of 53.5% with a 1 dB gain bandwidth of 12% (18.8–21.2 GHz). The proposed double-layer 45° LP TA shows enhanced bandwidth and simple design. Using a double-layer structure opens possibilities for TA design.

中文翻译：

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双层45°线性极化宽带和高效发射阵列天线

这封信介绍了双层45°线性极化（LP）宽带和高效发射阵列天线（TA）。所提出的元件由两个多谐振偶极子和四个金属通孔组成。偶极子放置在晶胞的对角线上，并印刷在介电基板的两侧。穿透基板并连接上偶极和下偶极的金属通孔可用于提高传输效率并获得较大的相移范围。所提出的元件实现了完整的360°相移范围，并在频带内具有平滑的斜率，并且在20 GHz时幅度损失小于1.5 dB。拟议的技术援助是设计，制造和测量的。测量和仿真结果一致。测量结果表明，建议的TA的最大增益为26。在20 GHz时为9 dBi，孔径效率为53.5％，而1 dB的增益带宽为12％（18.8–21.2 GHz）。拟议的双层45°LP TA显示出增强的带宽和简单的设计。使用双层结构为TA设计提供了可能性。