Design of an ultrathin and wideband metamaterial absorber based on resistance film and fractal frequency selective surface

Abstract

An ultrathin, wideband, polarization-insensitive and wide-angle metamaterial absorber is presented, which is based on one order Minkowski fractal double square loop (MFDSL) electric resonator structure and resistance film. The unit cell of this absorber consists of MFDSL, square resistance film, dielectric substrate and metal ground plane. The simulations and analyses of electromagnetic absorbing properties of this composite structure absorber are performed by the finite-difference time-domain method. The simulated reflection and absorption indicate that the absorption of the composed structure absorber is greater than 90% in a frequency range of 7.5-42 GHz. The simulated absorptions under different polarization conditions and incident angles indicate that this composite structure absorber is polarization-insensitive and of wide-angle. The further numerical simulation results indicate that the absorption of this absorber originates mainly from the absorbing mechanism of electromagnetic resonance and circuit resonance, the operation frequency range can also be adjusted by the design of the square resistance.