Dual-directional polarization insensitive multiband metamaterial absorber

Abstract

This paper presents the design, simulation, fabrication, and measurement of dual-directional polarization insensitive multiband metamaterial absorber (MMAbs). The MMAbs is designed at three resonating frequency in X-band. The structure of MMAbs consists of two-layers 0.8 mm-thick FR4 substrate with three concentric copper rings-shaped structures at different radius printed on the top and bottom surface of the combined substrates. A full copper layer is placed between two FR4 substrates to reduce transmittance. The circular ring-shaped is very symmetry in nature consequently, the designed MMAbs insensitive to all polarization angles of incident electromagnetic (EM) waves for normal angle of incident. From simulation, three absorption peaks are obtained at 8, 10, and 12 GHz with absorbance of 97.27%, 83.55%, and 78.49% respectively for normal incident angle of EM waves. The corresponding full width half maximum (FWHM) bandwidths are 5.39% (7.77 - 8.20 GHz), 3.32% (9.78 - 10.11 GHz), and 2.57% (11.91 - 12.22 GHz). The structure is capable to operate at wide variation angle of incident wave. The operating angle which the MMAbs can absorb at least 50% of incident EM wave are 67° for both TE and TM polarizations. The simulation results are verified through experimental result. Mutual agreement is achieved between simulation and experimental results.