左手材料的反射特性与负折射率行为

利用平板波导法研究了不同入射角度下周期排列开口谐振环负磁导率材料、周期排列金属杆负介电常数材料以及左手材料微波反射特性，并利用劈尖法研究了左手材料的负折射特性.实验结果表明：负磁导率材料反射率曲线形成反射峰，其对应的反射峰频率与材料的谐振频率一致；负介电常数材料反射率接近0dB；左手材料出现单个反射较小的反射峰，其峰值反射率随入射角度的增大而变大，即反射能力增强，且反射峰与透射峰有相对频移.劈尖法测量还表明，左手材料在9800MHz频率附近出现负折射现象，其折射率n为-0.796. 关键词： 左手材料 反射 负折射率

Reflection and negative refraction of left-handed metamaterials at microwave frequencies

We experimentally investigated the microwave reflection of the negative permeability material composed of periodical arrays of the copper split-ring resonators (SRRs).The negative dielectric materials are composed of periodical arrays of copper wires and left-handed materials(LHMs) in a planar slab waveguide, and the microwave is incident to the surface in different directions.We also investigated the negative refraction through a prism fabricated from the LHMs.The experimental results show that for the negative permeability materials,there is a reflection peak at the resonance frequencies of the SRRs, and the reflectivity of the negative dielectric material is closed to 0dB.A single smaller reflection peak occurs in the reflected curve of the LHMs,the reflectivity of which increases with the incident direction,that is,the reflection increases.The reflection peak has a shift with respect to the transmission peak. It is demonstrated that negative refractive index of -0.796 occurs in the LHMs at the frequency o 800MHz.