Step-wise homogeneous passive coatings for reduction of electromagnetic scattering from cylindrical metallic bodies

The total scattering cross section (or width) of strongly scattering metallic objects can be reduced by using various cloaks, which are complex structures with a limited frequency bandwidth. In many applications, however, dramatic reduction of total scattering is not always required, for instance, when backscattering reduction is the critical parameter. Moreover, the direction of illumination is sometimes known and scattering reduction for other illumination directions is not required. In these scenarios, it is possible to achieve the desired scattering reduction using much simpler manufactured devices. In this paper, we explore possibilities to reduce backscattering and forward scattering from cylindrical bodies for plane-wave illumination from a certain direction. The proposed scattering-reduction device is a shell formed by several sectors of different uniform dielectric materials. We compare the requirements on the material cover which are needed to reduce backscattering and forward scattering widths and outline the corresponding design approaches. We show that all-dielectric and easily realizable structures can effectively reduce total scattering without using active materials or non-uniform anisotropic materials. We develop and numerically test the method for TE-polarized incident waves, since this polarization is more critical for considered applications.