RCS reduction of dielectric cylinders using a simulated annealing approach

The reduction of RCSs (radar cross sections) of dielectric cylinders is of great interest from the point of view of enhancing the performance of antennas that use these cylinders as supports for radomes or feed systems. RCS reduction of dielectric cylinders under TM plane-wave illumination can be achieved by loading the cylinder with perfect electrically conducting narrow strips oriented parallel to the cylinder axis. For certain specific strip configurations and directions of radiation, it can be shown that the far fields radiated by the polarization currents are partially canceled by those produced by the conduction currents induced on the strips. This, in turn, has the effect of reducing the bistatic RCS of the isolated dielectric cylinder. The authors present a simulated annealing algorithm that simultaneously minimizes the bistatic RCS in different scattering angles, and/or frequencies, by searching for the optimal strip configuration. The scattering of a lossless dielectric cylinder measuring 1 by 0.2 wavelengths and characterized by a relative permittivity of 4 was minimized for a TM plane wave incident on the broad cylinder axis.<>