Propagation of microwaves in periodic layered media

We introduce a simplified structure made of periodic metallic layers on a glass substrate that offer a potentially simpler approach in building photonic crystals. Using microwave experiments and Fresnel formulas, we have investigated the refractive index properties of these structures. We have measured experimentally both the transmittance and the reflectance properties and found unambiguously that the refractive index of the periodic layered medias decreased depending on periodicity of the geometric arrangement, dielectric contrast and filling fraction of metallic layers. Our results show the effects of thin metallic layers on the refractive index, reflection and transmission properties of a multilayer periodic structure. It was shown that metallic layers lead to substantial transformation of interference patterns which can be interpreted as a result of interference in a uniform media with a small (n<1)refractive index.