Design And Research Of Wave Absorbers For Electromagnetic Metamaterials

In the 21st century,electromagnetic metamaterials open up a new field of materials science,which has quickly become a research hotspot due to its unique features not found in natural materials.Through the rational allocation of the geometric parameters of metamaterials,strange electromagnetic functions can be obtained,which are often not achieved by natural materials.Metamaterials are major innovations in the field of material design,It has important application value in the fields of new information technology,national defense industry,electronic warfare,absorbing materials and new energy technologies.In the military,absorbing material based on metamaterials also has very important application value in the field of stealth and electromagnetic compatibility and the unique properties of metamaterials enable the stealth of various physical mechanisms.Absorbing materials can effectively absorb and scatter incident electromagnetic waves and significantly reduce the return loss of the target object,and can significantly reduce the target's radar cross section(RCS).In this paper,a variety of absorbing bodies are designed according to the absorbing principle of electromagnetic metamaterials,and the absorbing characteristics of absorbing bodies are analyzed.The main work of the paper is divided into the following sections:(1)The research background and research status of metamaterials and absorbers are introduced.Relevant theories about absorbers are introduced,such as the definition of absorbance and the principle of impedance matching.(2)This wave absorbing body design concept for the direction:single-frequency-multi-band-wide band-ultra-wide band.First,we design a meta-material microwave absorber in the single-frequency terahertz band,and use the equivalent circuit method to study the polarization direction of the incident wave and the influence of structural parameters on its absorption performance.Secondly,a new type of cross-shaped absorber is designed by the model contouring method.The absorption of the absorber reaches 90%at the frequency of 2.64GHz.Subsequently,by adding a resonator of other shapes inside a cross-shaped absorber,a dual-band absorber was designed.In addition,a wideband super-material absorber with lumped resistance is designed.The absorption of the absorber is higher than 90%in 8.81-18.52GHz band,the absorption bandwidth reaches 9.71 GHz and the relative absorption bandwidth reaches 71.06%.Finally,through the multi-layer resistive film superposition of ways to achieve ultra-wide band characteristics,the first absorption band with absorbance higher than 90%is 9.81-66.24GHz and the absorption wide band reaches 56.43GHz.(3)By discussing the polarization direction of incident electromagnetic wave,simplifying the influence of contour processing,resonator combination,loading resistance,laminated structure and other factors on the absorption rate of various wave absorbers,and analyzing the RCS reduction of wave absorbers on target objects,The results show that the wave absorbing structure has good absorption characteristics to meet the demand.By analyzing the results of these five models,the mechanism of wave absorption in different structured wave absorbers is deeply studied.Research on various types of wave body,stealth technology,electromagnetic compatibility,etc.have a certain reference value.