Abnormal refraction of microwave in ferrite/wire metamaterials.
Abnormal refraction of microwave in ferrite/wire metamaterials.
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DOI：
10.1364/oe.19.015679
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发表时间：
2011-08
期刊：
影响因子：
3.8
通讯作者：
Hongjie Zhao;Bo Li;Ji Zhou;L. Kang;Qian Zhao;Weibin Li
中科院分区：
文献类型：
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作者：
Hongjie Zhao;Bo Li;Ji Zhou;L. Kang;Qian Zhao;Weibin Li
本文报道了在由铁氧体棒和金属丝两种结构组成的超材料中实验观察到的反常折射现象。负折射（NR）和正折射（PR）在由平行排列的棒和线构成的MM中被证明。NR和PR的频率可以通过施加的磁场一起动态地调节，并且PR发生在略低于NR的频率处。NR归因于同时负的有效介电常数和磁导率，PR由正的有效介电常数和磁导率产生，其中正的有效介电常数源自最近的杆和线之间的电磁耦合。通过使杆与线交叉以减少耦合，我们在由交叉排列的杆和线组成的MM中观察到了唯一的NR。理论分析定性地解释了这两种介质中微波的反常折射行为，反演的有效参数和场分布支持了理论分析。
We report the experimentally observed abnormal refraction in metamaterials (MMs) consisting of ferrite rods and metallic wires with two kinds of configurations. Negative refraction (NR) and positive refraction (PR) are demonstrated in an MM constructed with parallel-arranged rods and wires. The frequencies of both NR and PR can be adjusted dynamically and together by an applied magnetic field and the PR occurs at frequencies slightly lower than that of the NR. The NR is attributed to simultaneously negative effective permittivity and permeability, and the PR is resulted from positive effective permittivity and permeability with the positive effective permittivity originating from electromagnetic coupling between the closest rod and wire. By making the rod cross the wire to reduce the coupling, we observed sole NR in an MM consisting of the cross-arranged rods and wires. Theoretical analysis explained qualitatively the abnormal refraction behaviors of microwave for the two kinds of MMs and it is supported by the retrieved effective parameters and field distributions.