Design Of Electromagnetic Absorber With Large Angle Oblique Incidence

As an important supplement to traditional absorbing materials,the structured electromagnetic absorber has many advantages such as easy integration and flexible design.It has been widely used in the field of electromagnetic microwave and has received extensive attention from academic circles at home and abroad since its inception.Although after decades of continuous research and development,most of the research focuses on the traditional directions such as broadband absorption,low profile,and multiple frequency bands,and there are relatively few studies on oblique incidence absorption at different angles.There are many,although some scholars have conducted exploration and design,but there is very little progress,and new breakthroughs are urgently needed.On the basis of in-depth research on the relevant literatures and developments of structural electromagnetic absorbers at home and abroad,this paper proposes a new design of electromagnetic absorbers for large-angle oblique incidence electromagnetic absorbers with a design angle of more than 30° Methods,a broadband electromagnetic absorber with good performance in a wide angular range is designed,and finally the performance optimization scheme for the design of the absorbing structure is extended.The main work and research innovations of this paper are as follows:1)A method of designing an electromagnetic absorber based on the antenna reciprocity theory is proposed,and a scheme for converting an antenna design with a specific antenna radiation pattern into an oblique incidence electromagnetic absorber is obtained.The oblique incidence based on the antenna reciprocity design is obtained.The electromagnetic absorber corresponds to the characteristics of the antenna input impedance and the specific antenna radiation pattern.2)Based on the idea of the antenna reciprocity principle,on the basis of the traditional broadband electromagnetic absorber,the design of a broadband oblique incidence large angle electromagnetic absorber is proposed,which realizes the specific polarized wave absorption bandwidth from normal incidence to high angle domain Optimization improvements.The generalized extraction method of the equivalent circuit of the periodic structure under the oblique incidence is proposed,and the equivalent circuit of the designed broadband oblique incidence large-angle absorber at a certain angle is successfully extracted.3)Firstly,combining the scattering scheme of reducing the radar scattering crosssectional area with the design of the electromagnetic absorber,an electromagnetic absorber with diffuse scattering characteristics is designed,which innovatively expands the design idea of the absorbing structure.,Improve the electromagnetic absorber to reduce the RCS performance;finally,try to optimize the unit structure of the oblique incidence angle,so that it can ensure a certain operating bandwidth under a specific oblique incidence angle,and gives the optimized simulation results.