A Multiband Metamaterial Absorber with Concentric Continuous Rings Resonator Structure

This paper presents the design, simulation and parametric analysis of a concentric continuous ring resonator structure for a multiband metamaterial (MM) absorber. The unit cell of MM structure consists of concentric annular rings of different radii as well as width arranged in four different quadrants. The three layered proposed MM absorber design has an upper layer comprising of continuous annular ring structured sub-cells separated by a bottom laminated copper layer of FR4 substrate. The highly symmetrical annular ring structures in nature make this absorber insensitive to any polarization state of incident EM waves. The scattering parameter and absorption coefficient are obtained for the present MM absorber. The electric and magnetic fields are monitored to realize the behavior of MM structure. The absorbance for this MM absorber are also obtained as 98%, 98%, 96% and 92% at 7.102 GHz, 9.104 GHz, 12.558 GHz and 13.097 GHz frequencies respectively for the normal incidence of EM waves. The high absorbance makes this MM absorber suitable for various microwave applications including airborne and radar signal absorption.