Broadband perfect metamaterial absorber based on fractal structure

Broadband perfect metamaterial absorber has broad application prospects in the fields of radar target stealth, antenna design and electromagnetic protection. The existing multi frequency absorber will increase the size or thickness of the structure. This paper presents broadband polarization insensitive perfect metamaterial absorber based on fractal structure. Through the combination of fractal and circular structures, the bandwidth is extended without increasing the size of the structure. A simple equivalent circuit model has been proposed describing the absorption phenomenon to estimate the frequency of absorption of the proposed absorber. The simulated result shows that the absorber’s relative full width half maximum is 11.7%. The operating angles which the metamaterial structure can maintain 50% of the absorbance are 50 degrees. With rotational symmetry structure, the absorber is insensitive to the polarization. This structure is made and measured at X-band, the experimental results coincide well with the simulation results.