| This paper studies the electromagnetic shielding property of metal mesh underthe environment of HFSS software, which analyzes how the metal materials, theporous depth, the density of the porous surface and the porous configuration influencethe electromagnetic shielding effectiveness of monolayer metal mesh. On this basis,multilayer metal mesh which are compounded of different characteristic pores anddifferent materials are used to test the electromagnetic shielding characteristics inorder to find out the effective method to improve the electromagnetic shieldingeffectiveness of porous composite structural metal mesh.According to the structure of this paper, there are two parts. During the first part,the thesis pays more attention to the harm of electromagnetic radiation, and introducesthe concept of electromagnetic shielding, the current researches and types ofelectromagnetic shielding materials widely applied to the commerce, military and ourdaily life. At the same time, this paper proposes a new method that can be used tomeasure the shielding effectiveness of electromagnetic shielding material--Rectangular Waveguide Measurement. On the other hand, it also discusses how tomake good use of Rectangular Waveguide Measurement to test the electromagneticshielding effectiveness of metal mesh in detail.During the second part, some information about the experiments is introduced,which is also the core part of this paper. In this section, through a lot of contrastexperiments, it explores the influence of the material and porous characteristics on theelectromagnetic shielding effectiveness of monolayer metal mesh. Based on theanalysis of the electromagnetic shielding property of monolayer metal mesh, thispaper also discusses the electromagnetic shielding characteristics of the double layer porous composite structural metal mesh and analyzes the influence of differentcharacteristic pores on the electromagnetic shielding effectiveness of the porouscomposite structural metal mesh.The results of experiments have shown that the metallic conductivity has obviouseffect on the electromagnetic shielding effectiveness. Good metallic conductors withlow permeability, high conductivity and excellent electrical conductivity have a bettereffect on the shielding effectiveness of high frequency; the thickness of the metalmesh, which means the porous depth of metal mesh, has a great influence on theelectromagnetic shielding effectiveness. Within a certain range, the deeper the porousdepth is, the better the electromagnetic shielding effectiveness of metal mesh will be.Besides, porous surface density of metal mesh is one of the most important factorsthat restrict its electromagnetic shielding property. The ideal shield should be thosemetal materials which are complete and without any pores. Because the more poresthere are, the worse the shielding effectiveness will be. In the same situation, metalmesh with circular pores can reduce the attenuation of the shielding effectiveness; theelectromagnetic shielding effectiveness of the double layer porous compositestructural metal mesh is much better than the monolayer porous composite structuralmetal mesh; As for the porous composite structural metal mesh, the metal mesh withdifferent composite materials as well as porous dislocation has the best effect on theelectromagnetic shielding.For the porous composite structural metal mesh, according to the circumstance,we can combine the materials composite and the pores dislocation composite, increasethe number of electromagnetic wave’s reflection, and enlarge the absorption loss ofthe electromagnetic wave in order to improve the electromagnetic shieldingeffectiveness. |
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