The Design And Characteristics Analysis Of Multi-band Terahertz Absorber

Metamaterials absorber is a kind of artificial composite materials,it can through design the size of structure and the parameters of material reasonable to achieve perfect absorption.Based on the metamaterial absorber in THZ wave band has many potential applications,this article studies from the design of metamaterial absorber on terahertz band.There are two kinds of double belt metamaterials absorber structure have been designed in this article,duplex structure and tetragonal symmetry structure respectively,differentiate from the distribution of electric field and the surface current table to explain the absorption theory of the absorber,this paper expounds the relationship between the structure size on each structure with the absorption rate and the absorption frequency,analysis the absorption properties of the structure on TE and TM mode,it is concluded that duplex structure is the polarization sensitive structure,window type structure is not polarization sensitive structure.On the basis of the two kinds of metamaterial absorber,designes a three bands metamaterial absorber structure.Modeling and simulation,and prepare the samples,obtains the electromagnetic response characteristics of the three bands metamaterial absorber by simulation analysis and experimental testing,the absorber based on the unit structure produces three obvious absorption peak,at 0.59 THz,1.29 THz and 1.56 THz respectively and get the three absorption peak are 83.19%,99.19% and 99.96% by calculate.Then change the incidence model and the incident angle to analyzes the structure for polarization sensitivity and angle stability,for TE wave,this structure showes good incident angle stability,but for TM wave,the structure creates an additional peak when the incident angle increased.This paper discusses the additional peak from two aspects,they are the magnetic resonance and the interference theory,this paper also analyzes the structure of the electric field distribution and the surface current distribution and energy loss,explaines the absorbing mechanism of the structure.In addition,researches the wastage of the absorbing device structure from two aspects,the dielectric loss and the metal loss respectively,analyzes the various sizes of the structure with absorption rate and absorption frequency,the influence of each parameter is optimized,and obtains the three bands meta-materials absorbing structure with the most perfect absorption effect of absorption parameter eventually.