基于双磁介质层复合的超材料低频吸波体研究

本研究将磁性吸波涂层融入至超材料的结构设计中，得到了一种新型低频复合超材料吸波体，吸波体由环形电阻膜、双层磁性吸波涂层和金属背板组成。采用CST仿真软件计算了超材料吸波体的吸收性能，研究了吸波体各个结构参数对吸收性能的影响。仿真结果表明，设计的超材料吸波体厚度为2.5 mm时，在1.9和4 GHz处存在2个吸收峰，在1.59～6.59GHz频率范围内反射损耗低于-8dB，吸收带宽达到5GHz。通过吸波体电磁场分布对吸波机理进行了讨论。结果表明，吸波体低频吸收带宽的增加是由于表面的电阻膜图案改变了超材料吸波体的电场分布和磁场分布，促进了磁介质层的损耗。最后制备了吸波体样品并进行了反射率测试，实物测试结果与仿真结果基本一致，说明设计制备的吸波体具有优异的低频吸波性能，吸波带宽相比磁性吸波涂层大幅提高。

Research on Low Frequency Metamaterial absorber based on double magnetic dielectric layer composite

In this paper, the magnetic absorbing coating is integrated into the structural design of metamaterials, and a new low-frequency composite metamaterial absorber is obtained. The absorber is composed of annular resistance film, double-layer magnetic absorbing coating and metal back plate. The absorption properties of the metamaterial absorber are calculated by CST simulation software, and the effects of various structural parameters of the absorber on the absorption properties are studied. The simulation results show that when the thickness of the designed metamaterial absorber is 2.5mm, there are two absorption peaks at 1.9GHz and 4GHz, the reflection loss is less than -8dB and the absorption bandwidth is 5GHz in the frequency range of 1.59-6.59GHz. The absorbing mechanism is discussed through the electromagnetic field distribution of the absorber. The results show that the increase of the absorption bandwidth of the absorber is due to the change of the electromagnetic field distribution of the metamaterial absorber and the loss of the magnetic dielectric layer. Finally, the absorber samples are prepared and tested. The physical test results are basically consistent with the simulation results, which shows that the designed and prepared absorber has excellent low-frequency absorbing performance, and the absorbing bandwidth is greatly improved compared with the magnetic absorbing coating.