An ultra-thin compact polarization insensitive dual band absorber based on metamaterial for X-band applications

In this article, an ultra-thin compact polarization insensitive dual band absorber based on metamaterial for X-band applications has been presented. The unit cell of proposed absorber structure consists of resonator I and resonator II printed on the top of metal backed FR4 epoxy dielectric substrate of thickness 0.6 mm. The proposed structure offers two absorption peaks at the frequency of 8.51 and 9.12 GHz with peak absorption value of 99.33 and 99.49%, respectively. The FWHM bandwidth of proposed absorber structure at 8.51 GHz is 400 MHz (8.33 28.73 GHz) and at 9.12 GHz is 430 MHz (8.89 9.32 GHz). The absorptivity of the designed absorber structure has been also investigated under various polarization and oblique incident angles. The absorption behavior of the designed absorber structure has been studied by illustrating electric field and surface current distribution plots. Additionally, the absorption behavior of the proposed absorber structure has been also explained using input impedance plot. Dispersion diagram plot has been used to explain the metamaterial property of the designed absorber structure. The proposed absorber structure shows compactness of 0.173 lambda(o) and 0.185 lambda(o) and exhibits ultrathin thickness of 0.017 lambda(o) and 0.018 lambda(o) with respect to the absorption peaks of 8.51 and 9.12 GHz, respectively. To perform the experimental measurement, the proposed absorber structure has been fabricated. It is seen that the measured result shows good agreement with the simulated one.