Miniaturized broadband absorber based on fractal structure metasurface

A broadband metasurface microwave absorber with a miniaturized size is presented under two mechanisms. A frequency selective surface based on the Minkowski (MSK) fractal structure is constructed to provide a lower resonance frequency with the similar size, and the Salisbury screen is designed to create high-frequency resonance. Then, a second-order MSK fractal ring is loaded to realize impedance matching over the entire bandwidth. The absorption performance of the metasurface absorber (MA) proposed is validated by the equivalent transmission line model, the Smith chart, and the surface current distribution. The simulation results demonstrate an absorption bandwidth of 125% with an absorption rate of >90% over 0.3-1.3 GHz. The thickness of the proposed absorber is 0.075 λ , and the size of the unit cell is 0.1 λ . The developed absorber exhibits stable absorption performance for both TE and TM polarizations within an incident angle of 40 ° . The experimental results agree with those of full-wave simulation.