APPLICATION OF DOUBLE ZERO METAMATERIALS AS RADAR ABSORBING MATERIALS FOR THE REDUCTION OF RADAR CROSS SECTION

We introduce and investigate the applications of double zero (DZR) metamaterials (having the real parts of permittivity and permeability equal to zero) as radar absorbing materials (RAMs). We consider a perfectly electric conductor (PEC) plate covered by several layers of DZR metamaterial coatings under an oblique plane wave incidence of arbitrary polarization. Several analytical formulas are derived for the realization of zero reflection from such structures. The angle of reflection in the DZR metamaterials becomes complex, which leads to the dissociation of the constant amplitude and equiphase planes. Then several examples of the applications of DZR metamaterials (in nondispersive and dispersive conditions) as RAMs and zero reflection coatings are provided. The characteristics and parameters of the DZR metamaterial media are determined in each case. The method of least squares is used to optimize the DZR coatings for the minimization of reflected power, which uses the combination of genetic algorithm and conjugate gradient method (GA-CG) to benefit from their advantages and avert their short comings.