A Tri-band Metamaterial Absorber for Radar Cross Section Reduction.

In this paper, a new tri-band metamaterial absorber based on crossed sun fractal structure for Radar Cross Section (RCS) reduction is presented. The proposed metamaterial absorber (MMA) exhibits three distinct absorption peaks at 2.2, 5.9 and 6.8 GHz with peak absorption values of 97, 91.6 and 93.3 % respectively. The proposed MMA unit cell is printed on FR-4 substrate with thickness 1.6 mm (0.0117λ₀) and compact size 40 mm × 40 mm (0.293 λ₀ × 0.293λ₀), where λ₀ is the free-space wavelength with respect to the lowest resonance frequency. Thanks to the new proposed fractal sun shape with sharp edges, we achieve the highest absorption rate at the lowest resonant frequency in comparison with the other published works. In addition, the simple equivalent circuit model is proposed to analyze and predict the frequency of the absorption phenomena of the proposed design. Radar target is characterized by Radar Cross Section (RCS). The surface currents and electric field distributions have been illustrated to understand the mechanism of the structure. In this paper we simulated and calculated the RCS of Perfect Electric Conductor (PEC) and compared this result by a PEC covered by metamaterial sheet. The proposed absorber structure can be used in different applications such as electro-magnetic protections, military and medical applications. All simulation results are performed using the Computer Simulation Technology (CST) Microwave Studio 2018 software, Advanced Design System (ADS) 2017 software, and Mathworks simulation tool MATLAB ver. 2011. In this paper, a new tri-band metamaterial absorber based on crossed sun fractal structure for Radar Cross Section (RCS) reduction is presented. The proposed metamaterial absorber (MMA) exhibits three distinct absorption peaks at 2.2, 5.9 and 6.8 GHz with peak absorption values of 97, 91.6 and 93.3 % respectively. The proposed MMA unit cell is printed on FR-4 substrate with thickness 1.6 mm (0.0117 λ₀) and compact size 40 mm × 40 mm (0.293 λ₀ × 0.293 λ₀ ), where λ₀ is the free-space wavelength with respect to the lowest resonance frequency. Thanks to the new proposed fractal sun shape with sharp edges, we achieve the highest absorption rate at the lowest resonant frequency in comparison with the other published works. In addition, the simple equivalent circuit model is proposed to analyze and predict the frequency of the absorption phenomena of the proposed design. Radar target is characterized by Radar Cross Section (RCS). The surface currents and electric field distributions have been illustrated to understand the mechanism of the structure. In this paper we simulated and calculated the RCS of Perfect Electric Conductor (PEC) and compared this result by a PEC covered by metamaterial sheet. The proposed absorber structure can be used in different applications such as electro-magnetic protections, military and medical applications. All simulation results are performed using the Computer Simulation Technology (CST) Microwave Studio 2018 software, Advanced Design System (ADS) 2017 software, and Mathworks simulation tool MATLAB ver. 2011. [ABSTRACT FROM AUTHOR]