Artificial anisotropic chiral materials for decrease of reflection of electromagnetic waves from metallic surfaces

Paying attention to the possibility of making the covers with low reflection of electromagnetic waves we have analyzed the characteristics of the electromagnetic waves under the condition of transmission through the artificial anisotropic medium on the metallic layer. The boundary value problem for normal incidence of electromagnetic waves on stratified periodic structure we have solved in case of the following structure: air - artificial anisotropic medium - layer of metal - air. Amplitude and phase characteristics of reflected and transmitted waves were calculated depending on the parameters of a artificial anisotropic medium and metallic layer, and the complex influence of anisotropic and chiral properties was also investigated. We find the optimum features of the structure required for reducing the intensity of a reflected wave on the certain frequency, here we take into account the absorption of waves in the sample and metal. Aluminum is taken as a metallic substrate. The artificial material is dielectric with the metallic microspirals, inserted in it. The axes of spirals are oriented in the same direction. In this case the medium is characterized by uniaxial tensors of permittivity and chirality. For the orientation of the axes of spirals in the same direction the Nylon threads can be used, on which the spirals are reeled up. Samples of similar media were recently obtained at Stellenbosch University in Southern Africa. Our calculations allow to predict the experimental results in case of deposition of similar covers on the metallic substrate.