A Numerical Study On The Characteristic Of Electromagnetic Wave Absorbing For Composite Material With Core-shell Particles

The research and design of new type electromagnetism absorbing material is one of the hotspots in modern material design. It means a lot not only in military stealth technology, but also in reducing the interference of extra waves produced in microelectronics communications system, eliminating the electromagnetic radiation to people and preventing its pollution to the environment. As a new type of electromagnetism absorbing material, composite material with core-shell particles possesses many merits with which traditional materials can't be compared. It's preparation and the related researches on electricity, magnetism, acoustics and microwave have always been the focuses both at home and abroad.Based on the basic equations of electromagnetic field, this thesis adopts generalized self-compatible method, and educes equations of effective magnetic permeability and permittivity of composite material with core-shell particles, then comparing the characteristics between absorbers with and without core-shell particles. Using the method of transfer matrix, this thesis figures out the power reflection coefficient of reflection layers. The reflection coefficient of plate structure with a certain curvature is also discussed. By method of partitioning micro units, this thesis gets the relation between incidence angle and reflection coefficient. Furthermore, the design for the thickness of plate structure absorber with a certain curvature is optimized.According to the above equations, this thesis establishes a theoretical frame for the optimized designs of absorbing layers, and the design of both single and double layered absorbing layers are optimized. This thesis also discusses the absorbing characters of each electromagnetic wave absorbing layer which is composed of composite material with core-shell particles. Giving the power reflection coefficient in different incidence angles, wavelength of electromagnetic waves, and the thickness relation between absorbing layers, with the optimal aim of maximum power reflectivity, and with method of step by step search to fix on the best thickness of the electromagnetic wave absorbing layer. These researches offer reference for the design of absorbing layer with core-shell particles. Through comparison, this thesis concludes that the absorbing performance of absorbing layer with core-shell particles evidently better than traditional materials.