M.Yu. Zvezdina, Yu.A. Shokova, S.N. Zabelkin, D.S. Zaikin
Extensive development of metamaterials with unique properties gives an additional possibility of the antenna directivity pattern control. In particular, applying the negative refractive index materials in the coating allows changing the refraction coefficient phase and thus the electromagnetic field structure in the far field of the radiator placed near the coating.
In the paper the investigation results are given for both the electrical and magnetic properties of the metamaterial layers and layer position inside the coating influence on the directivity patterns of the elementary longitudinal electric dipole, elementary lateral magnetic dipole, elementary longitudinal magnetic dipole and elementary radial electric dipole. It is shown that the greatest influence on the radiator directivity properties has the coating with the magnetic properties less then one. Herewith, the main lobe width changes (the lobe shrinks) for the longitudinal electric dipole, when the magnetic properties of the upper level approach zero the changes are the greatest. The abovementioned effect is not so strong for the changes of dielectric properties of the coating.
The change of the magnetic properties of the coating for magnetic dipoles leads more to the directivity pattern form change than to main lobe width change. Herewith, the orientation direction for the main and first side lodes change and then the single lobe directivity pattern forms. Dielectric properties change leads to a small displacement of the main lobe and to the change in the side lobe levels.