ABSTRACT

An ultra-wideband metamaterial (MM) filter with steep cut-off is proposed at terahertz (THz) region. The filter is based on the flexible hybrid structure of copper (Cu)–polyimide (PI)–polymethacrylamide (PMI) multilayer, which reduces the mutual coupling in multilayer MMs. Simulation results prove that the central frequency of the filter is 125 GHz, while the square ratio reaches 0.92 and the relative bandwidth is up to 65%. In addition, it has excellent flat-top characteristics, and the stopband absorption exceeds 95%. Due to the strict symmetry of the structure, the filter shows polarization insensitivity. The transmission mechanism of THz wave is investigated by surface current distribution and the role of each layer in filtering is explored. This work may provide a further step in the development of broadband MM filters with high square ratio, which have potential applications in THz communications and sensors.

摘要

提出了在太赫兹（THz）区域具有陡峭截止频率的超宽带超材料（MM）滤波器。该滤波器基于铜（Cu）–聚酰亚胺（PI）–聚甲基丙烯酰胺（PMI）多层的柔性混合结构，可减少多层MM中的相互耦合。仿真结果表明，滤波器的中心频率为125 GHz，平方比达到0.92，相对带宽高达65％。此外，它具有出色的平顶特性，阻带吸收率超过95％。由于结构的严格对称性，滤波器显示出偏振不敏感。通过表面电流分布研究了太赫兹波的传输机理，并探讨了每一层在滤波中的作用。这项工作可能会为开发高平方比的宽带MM滤波器提供进一步的步骤，