Design, Simulation and Fabrication of Ultra-Wide-Band Electromagnetic Waves Absorber with Optimal Dimensions Based on Metamaterial

In this paper, an ultra-wide-band Metamaterial Absorber with simple structure and optimum dimensions and thickness is proposed for X-band applications. This structure design with using three split circular rings and its dimensions optimized with HFSS. The unit cell of the proposed absorber has low dimensions and thickness (thickness 0.066λ_0 at 10 GHz central frequency). An array of 24 × 24 elements of the proposed metamaterial absorber with dimensions of  〖170×170 mm〗^2 was constructed and evaluated in practice. The structural parameters of resultant Metamaterial including permeability (μ) and permittivity (ε) are extracted by using Nicolson- Rose method. The results of simulation and practical measurement, show that, almost in total X-band rang (of 7.3 GHz to 11.5 GHz), the structure of the absorption bandwidth is 90%. Also, the studing of the results shows that, there is a good agreement between the acting measurement and simulation. The designed structure was also tested for the angles of perpendicular and obliquely incident electromagnetic wave, that, up to 45 degrees, absorption bandwidth did not change much.