论文名称为“Wideband and Wide-Angle Single-Layered-Substrate Linear-to-Circular Polarization Metasurface Converter”。针对现有的单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，本文通过引入亚波长中心连接型单元和细直微带线等高极化隔离度结构，提出了一种基于单层介质的宽带宽角线圆极化变换表面。该周期单元由金属十字微带线和位于另一金属层上中心放置的水平微带线组成。该十字微带线的垂直臂穿过整个金属表面，类似于一个高通滤波器，在高于低截止频率范围内表现为宽传输通带。同时位于另一层的水平微带线在工作通带外高频段谐振，在其谐振频率以下也提供一个宽带响应。此外，两条垂直放置在十字微带线两边的短微带线用来增加相互垂直极化方向对应的传输系数相移量并优化两个传输通带。本文利用等效电路和ANSOFT HFSS软件分析，设计了单元尺寸仅为0.11×0.21个工作波长的线圆极化变换表面，该极化变换表面在很宽的工作频段内表现为90度相移量和宽角稳定性。实测样品结果显示，在正入射下，仿真/测量的相对3-dB轴比带宽高达69%/74%，并且在55度入射下，测量的相对3-dB轴比带宽为54%。在考虑插入损耗小于3和2 dB的情况下，测量的相对3-dB轴比带宽仍分别保持70%和55%。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=8826610

Abstract—A wideband and wide-angle linear-to-circular polarization con-verter (LCPC) based on a single-layer dielectric substrate is pro-posed. The converter element consists of a metal strip cross backed by a strip horizontally and centrically located on the other metallic layer. The vertical arm of the strip across the whole sur-face performs as a high-pass filter with a wide passband above a low cut-off frequency. Meanwhile, the horizontal strip resonates at a high out-of-band frequency and also offers a wideband re-sponse below the resonant frequency. Another two short strips vertically and horizontally placed around the crosses increase the phase shift caused by the crosses and improve both the pass-bands. Using equivalent circuit models and ANSOFT HFSS, an example of LCPC is designed with the overall element size of only 0.11 λ0 × 0.21 λ0 for a 90° phase difference and wide-angle stabil-ity over the wide operation band.  The prototype shows the sim-ulated / measured axial ratios (AR) below 3 dB over the band-width of 69% / 74% for a normal incidence wave and 54% for the oblique incident angle of 55° in y–z plane, respectively. With the insertion loss of less than 3 and 2 dB, the measured 3-dB AR bandwidth keeps 70% and 55%, respectively.

Index Terms—Linear-to-circular polarization converter (LCPC), wideband, wide-angle, single layer.