Study On Electromagnetic Characteristics Of Composite Material With Double-layered Spherical Particles

With the extensive application of electromagnetic wave communication, people have realized the dangers of electromagnetic wave, electromagnetic wave shielding will be a hot issue. It is the most intuitive way that We design and preparate electromagnetic shielding materials to absorb microwave, using protective materials to control and eliminat electromagnetic interference. Double-layer spherical particle material is a new composite material, which has outstanding characteristics of electromagnetic wave absorption.Firstly, in the micro perspective, this paper has researched the scattering and absorption properties of double-layer spherical electromagnetic particles. On the basis of the pherical particles'electromagnetic theory, the paper discussed how the parameters of the particle influence the scattering and absorption of electromagnetic waves.Then the evenly distributed spherical particles in the wax matrix layer are processed for equation,by the classical Maxwell-Garent formula and Bruggeman formula.Being a uniform absorbing material with stable dielectric constant and magnetic permeability,It is analyzed for the reflection coefficient and the transmission coefficient in macroscopic electromagnetic field. Finally, a kind of nano-Fe/C composite coating layer ball is observed for it's actual shape, and tested it's composite reflection coefficient and transmission coefficient.The study results showed that:designing and controlling the size of absorbent particle, the thickness of the outer, inner and outer layer of material can optimize the particle's performance of electromagnetic wave absorption properties. It is be Found that the double-layer spherical dielectric particle with magnetic iron core, compared to the particle with conducting and non-magnetic carbon core,attenuats electro-magnetic wave more obviously;however the outer layer coated with plasma particles on the ball has good electromagnetic wave absorption. For the double-layer composite, according to the reflection and transmission coefficients along with the changes of the thickness and the variation of frequency, the best thickness and wave frequency can be chosen, which has a certain significance for the preparation of the absorbing material.