In this work, a broadband polarization converter in transmission mode based on tri-layered metamaterial structure is proposed to realize asymmetric transmission and linear polarization conversion simultaneously. The proposed design model consists of a hexapolar split ring structure and two orthogonal sub-wavelength gratings embedded in two dielectric substrates. The appropriate parameters of the unit cell are optimized and selected. Sequentially, a prototype is fabricated and measured in order to confirm performance of the proposed design structure. The simulation and measurement results consistently demonstrate that the conversion polarization transmission coefficient is greater than 0.9 within the frequency region of 4.516.7 GHz, which is equivalent to 115% of the relative bandwidth. Based on the Fabry–Perot-like cavity theory, the working mechanisms of this structure have been discussed in detail. Thus, the proposed design structure is expected high potential applications in irreversible electromagnetic devices.

在这项工作中，提出了一种基于三层超材料结构的传输模式宽带偏振转换器，以同时实现非对称传输和线性偏振转换。所提出的设计模型由六极裂环结构和嵌入在两个介电基板中的两个正交亚波长光栅组成。优化和选择单元格的适当参数。随后，制造和测量原型以确认所提出的设计结构的性能。仿真和测量结果一致表明，在 4.516.7 GHz 频率范围内，转换偏振传输系数大于 0.9，相当于相对带宽的 115%。基于类法布里-珀罗腔理论，已经详细讨论了这种结构的工作机制。因此，所提出的设计结构有望在不可逆电磁装置中具有很高的应用潜力。