Design and analysis of an ultrathin X‐band polarization‐insensitive metamaterial absorber

This article investigates on the design and analysis of an ultrathin X‐band metamaterial absorber in the microwave frequency regime. The proposed structure consist of four‐fold symmetry, and it has been exhibiting 99.6% absorptivity at the frequency of 8.65 GHz with full width at half maximum (FWHM) bandwidth of 331.8 MHz (8.4777 GHz ‐ 8.8095 GHz). The metamaterial characteristics of the proposed unit cell are verified with the help of dispersion plot. The working mechanism of the proposed absorber structure has been explained here by the E‐field, H‐field and the impedance plots. The absorptivity of the proposed structure have been investigated at different polarizations angles. In addition to above, MTM property is also shown by plotting permittivity and permeability plots. At the resonance frequency of 8.65 GHz, the input impedance of the designed absorber is 371.6 Ω, nearly equal to the free space impedance value. The designed absorber is of ultrathin thickness ( λ 0 /40) with respect to center frequency f c = 8.65 GHz. The proposed structure has been fabricated and simulated results are experimentally verified for the fabricated proto‐type.