Broadening the absorption bandwidth of metamaterial absorbers by transverse magnetic harmonics of 210 mode.
Broadening the absorption bandwidth of metamaterial absorbers by transverse magnetic harmonics of 210 mode.
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DOI：
10.1038/srep21431
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发表时间：
2016-02-18
影响因子：
4.6
通讯作者：
Guan J
中科院分区：
文献类型：
--
作者：
Long C;Yin S;Wang W;Li W;Zhu J;Guan J
通过对正方形超材料结构的研究，我们发现这种结构的对角处的波的绕射激发出210模的横向磁谐(TM210次谐波)。相邻单元电池之间的多层重叠和有意调节的周期长度可以显著增强TM210的谐波，导致强吸收波段。在此基础上，提出了实现宽带、薄层多层超材料吸波材料的设计策略。在这一策略中，放置在棋盘“白色空白”中的大金字塔阵列由于其基波和TM210谐波而显示出两个孤立的吸收带，这两个吸收带进一步由来自棋盘“黑色空白”的小金字塔阵列的另一个吸收带连接。所设计的厚度为4.36 mm的MMA在7-18 GHz的全频段内的吸收大于0.9，比以往的设计方法在相同的h下宽了38%，为在不增加h的情况下扩展MMA的吸收带宽提供了一条有效的途径。
By investigating a square-shaped metamaterial structure we discover that wave diffraction at diagonal corners of such a structure excites transverse magnetic harmonics of 210 mode (TM210 harmonics). Multi-layer overlapping and deliberately regulating period length between adjacent unit cells can significantly enhance TM210 harmonics, leading to a strong absorption waveband. On such a basis, a design strategy is proposed to achieve broadband, thin-thickness multi-layered metamaterial absorbers (MMAs). In this strategy big pyramidal arrays placed in the “white blanks” of a chessboard exhibit two isolated absorption bands due to their fundamental and TM210 harmonics, which are further connected by another absorption band from small pyramidal arrays in the “black blanks” of the chessboard. The as-designed MMA at a total thickness (h) of 4.36 mm shows an absorption of above 0.9 in the whole frequency range of 7–18 GHz, which is 38% broader with respect to previous design methods at the same h. This strategy provides an effective route to extend the absorption bandwidth of MMAs without increasing h.