Dual-band, polarization-insensitive, and wide-angle ultra-thin metamaterial absorber with interference theory analysis

We proposed an ultra-thin absorber, which consists of a two dimensional metallic Jerusalem cross array and a metallic ground plane separated by a dielectric layer, with its thickness is about λ/44 at the lowest resonant frequency. The simulated results indicate that this structure can perform absorbing peaks at dual resonant frequencies 3.25 GHz and 6.77 GHz with the absorption of 99% and 96%, respectively. In addition, the absorber is also insensitive to the incident angle and polarization. The structure is thereafter fabricated and experimental absorption measurement shows good agreement with the simulated one. Finally, the interference theory is introduced to analyze and elucidate the absorption mechanism. The calculated absorption results of the proposed absorber coincide well with the simulated one. Therefore, the simulated and experimental results verify the validity of the theoretically analytical method for this type of absorber.