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 0 dB. 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 of 9800 MHz.