Scattering characteristics of a cylindrical reflector covered with a general bi-isotropic layer

The scattering characteristics of an electric line source radiating in the presence of a bi-isotropic coated circular cylindrical reflector have been investigated using numerical calculations. The analytic expressions of the electric and magnetic fields in the bi-isotropic coating and the background medium have been found using the wave-field decomposition approach. It is studied that a bi-isotropic coating enhances the gain in the forward direction as compared to chiral, Tellegen, and dielectric coatings. It is found that for a thin coating layer, the scattering gains in the forward direction for chiral and bi-isotropic coatings are almost the same. It is investigated that a specific type of bi-isotropic coating can be used to significantly enhance the scattering gain in the forward direction. This type of enhanced forward direction scattering gain is preferred in point to point communications. On the other hand, it is found that a specific type of Tellegen coating significantly reduces the scattering gain in the backward direction. This phenomenon of reduced gain can be used to hide a cylindrical reflector in the backward direction. A comparative study of the scattering gains for realistic bi-isotropic and low-loss dielectric coatings has also been discussed.