Performance of a Metamaterial Absorber in Radar Cross Section Reduction

Abstract

This paper experimentally investigates the mono- and bistatic scattering cross section of an electrically large (approx. 16 wavelengths) metallic cube and cylinder coated with a metamaterial absorber at W-band frequencies (wavelength of approx. 3 mm). A simple metamaterial absorber composed of a metallic array of sub-wavelength sized capacitively loaded strip inclusions printed on top of a thin and grounded dielectric layer is designed and fabricated for this purpose. The performance of the absorber in radar cross section reduction is verified by comparing the scattering patterns of the coated and uncoated objects. It is shown that the performance of the absorber in scattering cross section reduction is closely related to the specular reflection coefficient of a flat and infinite sample of the absorber, and the absorber reduces scattering by approximately 10 dB in specular as well as non-specular directions around 94 GHz. The paper covers the whole range of performed activities from the design and fabrication of the absorber, to the numerical and experimental specification of the reflection coefficient of a flat sample, to the experimental demonstration of the effectiveness of the absorber in radar cross section reduction.