An ultra-thin polarization independent compact fractal shaped metamaterial absorber

In this paper an ultra-thin polarization-independent compact metamaterial absorber has been proposed where the unit cell contains single fractal shaped square structure. The geometrical dimensions of the fractal structure have been designed in such a way that the structure exhibits absorption at 4.17 GHz and 11.16 GHz. Due to the four-fold symmetry of the structure, the absorber is polarization-independent in nature. The proposed structure has been studied under oblique incidences for TE and TM polarizations where it behaves as absorber upto 45° incident angles in both the cases. The structure is only 1.6 mm thick (~ λ0/17 with respect to higher absorption frequency), making it ultra-thin in nature.