A generic approach to boundary reflection in periodic media

Waves in periodic media, whose propagation is governed by nearest neighbour interaction, are investigated. The reflection and transmission coefficients are derived for a plane wave incident from medium 1 upon medium 2, without invoking common approximations. The derivation is valid for a class of waves including magneto- and electro-inductive waves, waves on short loaded dipoles, nanoparticles, coupled waveguides and acoustic waves in monatomic media. For this last case hitherto unknown microscopic reflection and transmission coefficients are derived and shown to reduce in the continuous limit to the well-known expressions in terms of acoustic impedances. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 200641.20.Jb Electromagnetic wave propagation; radiowave propagation,

Positive and negative refraction of magnetoinductive waves in two dimensions

Previous studies of magnetoinductive waves in homogeneous media with resonant elements consisting of capacitively loaded metallic loops are extended to the case when a single wave from one medium is incident upon another one. The relationship between the input and output angles and the reflection and transmission coefficients are determined with the aid of the dispersion equation for different scenarios. An expression is obtained for the power density vector, and it is shown that its component perpendicular to the boundary is conserved across the boundary. Using different configurations of the elements it is shown that both positive and negative refraction may occur. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2005