论文名称为“Dual-band miniaturized linear-to-circular metasurface polarization converter with wideband and wide-angle axial ratio”。针对现有的双频线圆极化变换表面宽带和高入射角稳定性不能兼顾的问题，该文提出了一种基于小型化单元的双频宽带宽角线圆极化变换表面。该周期单元由三层金属面组成，并由两层介质隔开。顶端金属层结构和底端一样，均为沿y极化方向放置的两条金属微带线和伴有四个枝节的“I”型微带线复合结构。中间金属层包括沿x极化方向放置的一条无限长金属微带线和两条“I”型微带线。依托相互垂直的“I”型微带线分别产生的宽传输通带，该线圆极化变换表面在两个工作频段能表现为宽带响应。与上一个工作相比，因相互垂直子结构被放置于不同金属层，单元尺寸和交叉极化分别减小了60%和10 dB。基于小型化单元，该线圆极化变换表面具有高入射角稳定性。为验证设计，本文对K/Ka波段线圆极化变换表面样品完成了加工和测量。在垂直入射下，仿真/实测的轴比分别在低频段15-20.8 GHz (32.5%)/15-21.2 GHz (34.3%)和在高频段26.9-30.2 GHz (11.6%)/27.4-29.8 GHz (8.4%)小于3 dB。在45度入射下，测量的相对3-dB轴比带宽在双频段仍保持30%和11.7%。工作主要完成人王洪斌、程钰间、陈志宁。

论文链接：https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9445577

Abstract—A dual-band miniaturized linear-to-circular polarization converter (LCPC) metasurface with wideband and wide-angle axial ratio (AR) is proposed and demonstrated. The metasurface is formed with periodic arrays of unit cells. The unit cells consist of three metallic layers separated by two substrates. The top and bottom metallic layers contain the identical cells with two metal strips and an “I”-type strip with four stubs for y -polarization each. The middle metallic layer comprises an infinitely long metal strip and two “I”-type strips for x -polarization. The LCPC performs a wideband response in both operating bands with the wide passbands generated by the orthogonal “I”-type strips. Prototyped K -/ Ka -band design shows that the simulated/measured AR remains below 3 dB over the lower bandwidth of 15–21.2 GHz (34.3%)/16.3–21.1 GHz (25.7%) and higher bandwidth of 27–30.3 GHz (11.5%)/27–29.8 GHz (9.9%) under normal incidence in y−z plane, respectively. For a 45° incidence, the measured AR still achieved the 3 dB bandwidth of 33.7%/9.4% in both the bands. The study shows that by virtue of orthogonal structures placed at different layers, the element size and the cross-polarization level are suppressed by 65% and 10 dB, respectively, compared to the previous work. Furthermore, the LCPC with the miniaturized elements shows wide-angle response in both the bands.

Index Terms—Dual-band, linear-to-circular polarization converter (LCPC), wide angle, wideband.