electromagnetic waves diffraction
Advent of metamaterials as the artificial media having relative capacitivity and permeability less then 1 or even negative as well as the possibility of using the metamaterials in various branches of radio engineering calls forth a vivid interest for electromagnetic waves diffraction on such kind of media. One of the applied aspects in these investigations is the research of electric dipole directivity pattern near the multilayer surface including metamaterials.
The electric dipole directivity pattern near four-layer structure “free space-metamaterial-dielectic-free space” is investigated in the paper. The analysis of metamaterial parameters change influence at various dielectic parameters is also carried out.
The presence of the metamaterial with relative capacitivity, , and/or permeability, , less then 1 causes the total reflection effect at the angles or . It leads to a significant change of the electric dipole directivity pattern. For example, at and for the metamaterial layer the directivity pattern is defined by the next layer parameters. At the same time when and the directivity pattern practically coincides with the one of the dipole placed above the conducting surface in a distance equal to the one of the metamaterial layer.
Likewise at and for the metamaterial layer the directivity pattern is also defined mainly by the next layer parameters. But at and a sudden narrowing is observed and the maximum position depends on height of dipole placing over the next layer.