Study On Equivalent Electromagnetic Model Of Anisotropic Microwave Absorbing Honeycomb Structure

Stealth technology is an important research direction of modern military development,and structural absorbing materials as an effective means of stealth technology have received great attention.The honeycomb structure not only has the characteristics of light weight,but also has the advantages of high rigidity and high strength due to its special structure.The honeycomb material coated with a waveabsorbing coating has excellent electromagnetic and mechanical properties.Therefore,it is widely used in a variety of different structures(low-weight antenna reflectors,radomes and other low observable structures,etc.)components,attracting more and more scholars' attention and research.The equivalent electromagnetic parameters(permittivity and permeability)have important guiding significance for the design of honeycomb absorbing materials.Researchers generally need to obtain equivalent electromagnetic parameters through experimental measurement methods,and the experimental process is often complicated and there are measurement errors,so they fully consider the influence of the geometric parameters and physical parameters of each component of the honeycomb structure on the equivalent electromagnetic parameters It is very important to establish theoretical models of honeycomb substrate parameters,coating parameters and equivalent electromagnetic parameters.In this paper,we take the anisotropic honeycomb structure as the research target,considering the actual structural parameters and coating parameters of the honeycomb,an anisotropic equivalent electromagnetic parameter model is established based on the equivalent medium theory and.The experimental results and software simulation results show the validity of the theoretical model.The main research contents of this article are as follows:(1)An anisotropic equivalent electromagnetic parameter inversion method;based on the dispersion relationship of different polarized waves in the material and the scattering parameters at different incident angles,the anisotropic electromagnetic parameters of the material are inverted under two polarization modes.Based on this method,the application of the actual honeycomb structure is explored,and the results show that the method is applicable to both uniaxial anisotropy and biaxial anisotropy honeycomb structures.(2)Based on the principle of the layered anisotropy model method,the equivalent electromagnetic parameters of the special-shaped honeycomb structure are studied.Aiming at the shortcomings of the model,the equivalent medium theory is used to equivalent the honeycomb absorbing coating and the substrate.The model was revised accordingly,and a new model of the cellular structural parameters and equivalent electromagnetic parameters was established.The feasibility and accuracy of the model are verified by simulation and experiment.(3)Based on the anisotropic equivalent electromagnetic parameter model method,the existing side-incident reflection coefficient theory is explored,and the reflection characteristics of the regular honeycomb structure under the conditions of electromagnetic wave perpendicular incidence and oblique incidence sidewalls are studied.And the overall honeycomb structure is equivalent to a homogeneous medium under the condition of oblique incident sidewall,and the theoretical model of reflection coefficient of the honeycomb structure oblique incident sidewall under different polarization modes is given.In addition,the reflection characteristics of the incident on the honeycomb side were explored through simulation and experiment,which confirmed the accuracy of the theoretical model.The results show that the combination of anisotropic equivalent parameter model method and side-incident reflection coefficient theory can accurately predict the absorbing characteristics of the honeycomb structure,which has theoretical guiding significance for the design of honeycomb materials.