Research Of Electromagnetic Absorber Based On Metamaterial

As a new kind of artificial material,the electromagnetic metamaterial has super physical properties which cannot be found in nature.The metamaterial absorber(MA),which inherits the advantages of metamaterial,has great potential in applications of energy harvesting and electromagnetic shielding.Based on the concept of metamaterial absorber,several types of MAs are designed in this dissertation to solve the shortcomings of the current electromagnetic absorbers such as narrow working frequency band,poor flexibility and low light transmittance.The main content includes:1.Two kinds of broadband metamaterial absorbers based on single-layer and multilayer resistance film were proposed.For the single-layer structure,it can absorb more than 90% of the incident electromagnetic wave in the frequency range of 6.58 ?16.38 GHz,covering the whole X-band and part of Ku band.The sample of 13×27array was fabricated,and the absorption rate of more than 90% was achieved over a wide frequency range(7 ? 16.4 GHz).For the multilayer structure,high absorption was achieved in the ultra-wideband range of 2.95 ? 18.79 GHz,and the relative absorption bandwidth reaches up to 153%.2.An optical transparent ultra-wideband metamaterial absorber based on Indium Tin Oxide(ITO)was presented.The structure can achieve high absorption in the frequency range of 10 ? 75.5 GHz.The surface current distribution was studied and the absorption mechanism was explained.The absorption dependence on the surface resistance of different ITO layers was investigated.A sample with a total size of 276mm×276 mm and a 16×16 cell array was fabricated.The experimental results are consistent with the simulation results,which verifies the correctness and feasibility of the design.The transmittance of the sample was measured by UV-Vis spectrophotometer,and the average transmittance of the sample in visible light band was 60%.3.A triple-band flexible metamaterial absorber was designed.By using flexible substrate instead of the traditional rigid medium substrate,the proposed structure can conformal with the complex objects.The characteristics and absorbing mechanism of the designed flexible metamaterial absorber were studied.The influence of the parameters on the absorption performance was also investigated.A sample of 20×30array was fabricated and the experimental results are in good agreement with the simulation.