Modeling And Application Research Of Electromagnetic Parameters Of Honeycomb Absorbing Structures

With the high integration of electronic equipment,electromagnetic compatibility（EMC）has become a necessary condition for the stable and efficient operation of electronic equipment,and the research of electromagnetic wave absorbing materials has become an important branch of EMC.Because of its unique hollow structure and good mechanical properties,honeycomb materials have the advantages of light weight,high specific strength and specific stiffness,good thermal insulation and shock absorption effects,and can be applied to load-bearing parts.Adding an absorbing coating and optimizing the design,it has excellent absorbing performance.Therefore,the research of honeycomb absorbing materials has attracted more and more researchers’attention.In order to achieve a good absorbing effect of honeycomb absorbing materials,it is very important to study its electromagnetic parameters.The equivalent electromagnetic parameters（equivalent dielectric constant and equivalent magnetic permeability）of the honeycomb absorber can be obtained through experiments.However,the experimental period is long and the process is complicated,and the experimental results may be biased due to environmental influences.By studying the influence of various structural parameters and parameters of the absorbing functional layer on the reflection coefficient,a relationship model between the geometric parameters,electromagnetic parameters,and electromagnetic transmission characteristics of the honeycomb absorbing structure is established.Based on this model,it is very important to guide the design of honeycomb absorbing materials.In this paper,the aramid paper honeycomb is taken as the research object,and the effect of the unique physical size structure of the honeycomb absorber on the equivalent electromagnetic parameters is considered.An equivalent electromagnetic model of the honeycomb absorber is established,and the validity of the model is verified by experiments..Based on the equivalent medium theory and the Euclidean norm,the paper analyzes the effect of the physical size parameters of the honeycomb absorber on the equivalent electromagnetic parameters.The specific parameters are as follows the wall thickness w of the honeycomb,the edge length r of the honeycomb,the height h,The dielectric constantε₁ and permeabilityμ₁ of the main body,the thickness t of the absorbing coating layer,the dielectric constantε₂ and the permeabilityμ₂ of the absorbing coating layer.Finally,the theoretical model of equivalent electromagnetic parameters of honeycomb absorbing material is established.The theoretical model is verified by two methods:electromagnetic simulation software and experimental measurement.The reflectance calculated by the equivalent parameter model proposed in the paper in the microwave band 2-18GHz agrees with the simulation results and experimental results.In this paper,based on the proposed biaxial anisotropic equivalent electromagnetic parameter model and transmission line theory of uniform honeycomb absorbing materials,the gradient honeycomb structure material is regarded as a multilayer composite material.For each layer of honeycomb material,the electromagnetic parameters are calculated according to the proposed biaxial anisotropic equivalent parameter model,and then the transmission line theory calculation can effectively predict the absorption characteristics of the gradient honeycomb absorbing material.In the microwave frequency range 2-18GHz,gradient honeycomb absorbing materials with a height in the range of 30mm have been simulated by software,and the calculated reflectivity is consistent with the reflectivity simulated by CST.Drawing on the NRW inversion method,this paper considers the effect of the gradient honeycomb wave absorbing material structure on the equivalent electromagnetic parameters,introduces the gradient structure dielectric constant imaginary part correction factor,and establishes the equivalent electromagnetic parameter Acting model.In the range of 2-18GHz,the reflectivity results calculated using the electromagnetic parameters of the model inversion are basically consistent with the simulation results of the electromagnetic simulation software and the experimental results..In summary,this paper studies the equivalent electromagnetic parameter model of the honeycomb absorbing structure,and analyzes the effect of the physical structure size on the equivalent parameter.The established theoretical model of equivalent electromagnetic parameters has guiding significance for the design and application of honeycomb absorbing materials.