Research And Design Of Electromagnetic Metamaterials Based On Digital Coding

Electromagnetic metamaterials are a new class of materials emerging in the 21 st century.Due to their unique properties,they have attracted the attention of scientists,and their theories have been applied in the fields of physics,chemistry,materials,electronic communications and modern military.The proposal of the concept of digitally encoded electromagnetic metamaterials makes the design of electromagnetic metamaterials flexible and changeable,enabling better electromagnetic properties and wider application scenarios.The digitally encoded electromagnetic metamaterial controls the electromagnetic wave through the design of the encoding sequence,and finally realizes the reduction of RCS.In this paper,the application of digitally encoded electromagnetic metamaterials to the control of electromagnetic waves in the field of radar cross section reduction is studied.The main contents are as follows:According to the equivalent medium theory and generalized Snell’s law,several electromagnetic metamaterial unit structures are designed.The designed unit structure can achieve a reflection coefficient below-10 d B in the frequency range of 25GHz-40 GHz,and has good absorption properties characteristics,and Each unit structure has a different reflection phase response,which lays the foundation for the subsequent design of digitally encoded metamaterials.Aiming at the problem of stable phase difference between the unit structures of digitally encoded electromagnetic metamaterials,a 1-bit digitally encoded metamaterial is designed based on the design of electromagnetic metamaterial unit structures and based on the reflection phase difference.The digitally encoded metamaterial unit structure It has a stable phase difference in the frequency range of 30GHz-40 GHz,and when the incident angle and azimuth angle of electromagnetic waves are shifted by a certain angle,the stable phase difference can still be maintained.According to the working principle of digitally encoded metamaterials,taking the encoding sequence“00001111…/00001111…” as an example,the scattering properties of digitally encoded electromagnetic metamaterials are analyzed.The analysis results show that digitally encoded metamaterials can realize scattering beam control through encoding sequences.When the incident angle and azimuth angle are shifted by a certain angle,the scattered beam can still be controlled.Considering digitally encoded electromagnetic metamaterials,the scattered beam can be flexibly controlled by the design of the encoding sequence,thereby realizing RCS reduction.In the design process of digitally encoded electromagnetic metamaterials,it is necessary to find the optimal encoding sequence to achieve the best electromagnetic properties.Aiming at the problem of coding sequence optimization,the related coding sequence optimization algorithm is studied,and through the research and analysis of the related coding sequence optimization algorithm,based on the related theory of digitally coded electromagnetic metamaterials,an adaptive particle swarm genetic hybrid optimization algorithm is proposed.Compared with the traditional intelligent optimization algorithm,the algorithm has faster convergence speed and better global optimization ability.Finally,the digitally encoded electromagnetic metamaterials are rearranged according to the optimized encoding sequence.The simulation results show that it can achieve a RCS reduction of more than 20 d B in the frequency range of 20GHz-60 GHz,and can achieve a maximum RCS reduction of 35 d B.By analyzing and comparing the scattering properties and RCS reduction properties of metamaterials formed by different coding sequences,it is verified that digitally encoded metamaterials can flexibly control electromagnetic waves through the design of coding sequences,thereby achieving better RCS reduction.