Design and preparation of an ultrathin broadband metamaterial absorber with a magnetic substrate based on genetic algorithm

High-efficiency microwave absorption materials are widely used in electronic equipment and communication facilities. This study aims to develop a broad-bandwidth metamaterial absorber based on the magnetic substrate with a central frequency selective surface (FSS). It is however, different from the strategy of expanding the bandwidth for metamaterial absorbers reported in other literatures, in this study, a unique development strategy that involves selecting the most suitable magnetic substrate from a database using genetic algorithm is adopted. By adding an optimized FSS layer to the magnetic substrate, its loss performance and impedance matching performance are considerably improved, and the resulting metamaterial absorber exhibits excellent absorption properties. At a thickness of 3.1 mm, the reflection loss in the range from 2.5 to 17.2 GHz is below –10 dB, which is significantly better than the values reported in previous studies. In addition, the prepared metamaterial absorber possesses excellent absorption characteristics under oblique incidence conditions. The strategy proposed in this study leads to the successful development of a high-efficiency metamaterial absorber and represents a more effective approach than those previously used in the field.