Research On The Equivalent Model Of Electromagnetic Super-surface Impedance Plate

In recent years,with the rapid development of electromagnetic technology in various fields,electromagnetic metamaterials have been explored and studied by more and more scholars because of their special electromagnetic properties that traditional materials cannot match.Compared with traditional artificial electromagnetic materials,new artificial electromagnetic surfaces have many advantages,such as thin thickness and low loss,which have attracted great attention from the academic community.Due to the special structure of the surface unit of the new artificial electromagnetic surface,in the actual computer electromagnetic simulation software,it needs to consume a large amount of simulation calculation memory and a long simulation calculation time.Such shortcomings cause it to be complicated in the actual engineering design.Therefore,this paper uses an equivalent impedance model to replace the actual artificial electromagnetic surface structure for electromagnetic simulation calculations.Compared with the actual artificial electromagnetic surface unit structure,the equivalent impedance model greatly reduces the simulation time and simulation memory during the simulation calculation.It assists the design of the artificial electromagnetic surface unit.Time can greatly improve efficiency.The main research work of this dissertation is the derivation of the equivalent impedance plate model and the analysis of the application scenarios,and the equivalent impedance model is used to assist in the design of a beam deflection device based on artificial electromagnetic surface suitable for the L-band.The main work arrangement of this paper is as follows:Firstly,two new synthetic methods of artificial electromagnetic surfaces are introduced.The first type is the phase shift method based on the generalized Snell's law,and the second type is the surface electromagnetic susceptibility based on the generalized sheet transition conditions(GSTCs).(surface impedance method),and analyzed the relationship between the Huygens artificial electromagnetic surface design method and the surface electromagnetic susceptibility method,using a simplified solution method.Based on the principle of equivalence,the modeling process of the equivalent impedance film is derived,and the design process of the artificial electromagnetic surface equivalent to the surface impedance film is obtained.Based on this process,the equivalent surface impedance film model of the non-thickness metal disc is obtained by simulation,and The reliability of the model is verified by scattering simulation,and then the applicable scenarios of the model are verified,including whether it is applicable to the metal patch model with dielectric substrate,and the influence of the thickness of the artificial electromagnetic surface element on the equivalent impedance patch model is limited.The effect of the sparseness of the array on the equivalent model,the effect of the complex element model on the impedance plate,and the effect on the equivalent model when electromagnetic waves are incident obliquely.Finally,the changes of the scattered near-field electric field between the artificial electromagnetic surface and the equivalent impedance plate are analyzed.The actual array antenna with reflector is combined with the finite artificial electromagnetic surface element array.At the same time,the equivalent surface impedance plate model and the actual antenna array model are used for joint simulation to verify that the equivalent impedance plate model is in the actual antenna radiation wave.In addition,the model of the equivalent surface impedance film in the case of low transmission coefficient has been modified to reduce the electromagnetic characteristic error of the equivalent surface impedance film in the case of low transmission coefficient and the original model.Finally,using Huygens' principle and generalized Snell's law,a 45° beam deflection surface structure suitable for 2.5 GHz linear polarization was simply designed.First,an equivalent surface impedance plate array was designed using the equivalent impedance plate model and tested.In simulation,the specific artificial electromagnetic surface unit structure is found according to the impedance value distribution,and the arrangement and combination are performed.The artificial electromagnetic surface structure of rectangular patch and rectangular ring structure is used.Finally,the beam deflection characteristics of the two are compared,the simulation result has a small error,which shows the high efficiency of the impedance plate model in the rapid design of electromagnetic hypersurfaces.