Structural Design And Influencing Factors Analysis Of Electromagnetic Metamaterial Absorber

Metamaterial absorber is an array structure consisting of periodic absorbing units,which can realize the regulation of electromagnetic waves by artificial design.Because it usually has ultra-thin geometric size and high-frequency working band,it can break the limitations of traditional absorber and has attracted the attention of the academic community.After years of research,metamaterial absorbers have been widely used in military stealth,improving antenna transmission and reception characteristics,and prevention of electromagnetic pollution.At present,the research on metamaterial absorber mainly focuses on structural design,but the designed structures still have the problem of the not-high-enough absorption rate,the not-wide-enough working band,and only-few-frequency perfect absorbing.Therefore,the composition structure of the metamaterial absorber is studied in this paper,focusing on the relationship between the loss layer structure,geometric parameters,the composition of the dielectric layer and the absorbing properties.The main works are as follows:(1)Three types of metamaterial absorbers with different loss layer structures are proposed,which are tree-branch-shaped,mi-shaped and wind-mill-shaped metamaterial absorbers.All three metamaterial absorbers have good characteristics of perfect absorbing,broadband absorbing and multi-angle incidence,the latter two are also polarization insensitive.(2)The effects of the loss layer’s structure and geometric parameters on the performance of the matamaterial absorber are studied.By comparing the absorbing curves under different geometric parameters of the loss layer,the results show that the absorbing performance of the metamaterial absorber is mainly determined by the structure of the loss layer.The smaller the distance between its components,the better the absorbing performance.The greater the change of its geometric parameters with a greater surface current intensity,the more obvious the influence on the absorbing performance.(3)The effects of the dielectric layer’s material which is composed of two kinds of materials on the performance of the matamaterial absorber are studied.By comparing the equivalent impedance and absorbing characteristics of the absorber under different dielectric layers’ materials,the results show that the absorbing performance of the metamaterial absorber is mainly determined by the top-layer material of the dielectric layer,and the greater the tangent value of the loss angle,the better the absorbing performance.