Research Of Design And Beam Regulation Of Reconfigurable Intelligent Surface

With the large-scale commercial application of 5G,the global network capacity has increased exponentially every year.Due to the characteristics of low cost,low energy consumption,and programmable,the Reconfigurable Intelligent Surface(RIS)has important application prospects in future 6G communications.In this paper,RIS is taken as the research object,and the structure design and beam control of RIS are stutied.The main research content are as follow:1、Based on the 1 Bit RIS,the electromagnetic waves are scattered into 6 reflected beams.Firstly,through the direction change of the metal rhombic structure,a cell structure with high polarization conversion efficiency and reflection phases of 0° and 180° can be obtained in the4-33 GHz wide frequency band.Secondly,a two-dimensional coding sequence with 6 reflected beams is artificially designed.The 1 Bit unit structure is arranged according to the artificially designed two-dimensional coding sequence,and a 1 Bit RIS composed of 8×8 grid super units is constructed.The final simulation results show that six reflected beams can be realized in the4-33 GHz wide frequency range.2、Based on the 2 Bit RIS,the electromagnetic waves are scattered into 18 reflected beams.First,through changing the size of the upper metal patch,four RIS unit structures with a phase difference of 90° in the frequency range of 17-19 GHz were designed.Secondly,a two-dimensional coding sequence with 18 reflected beams is designed.The 2 Bit unit structure is arranged according to the artificially designed two-dimensional coding sequence,and a 2Bit RIS composed of 8×8 grid super units is constructed.The final simulation results show that 18 reflected beams can be realized in the 17-19 GHz frequency range.3、Design a RIS with uniform scattering beams based on genetic algorithms.Firstly,the genetic algorithm is used to design an optimized coding sequence that can uniformly scatter the incident plane wave.Then,based on the 2 Bit RIS unit structure,a 2 Bit optimized coding sequence metasurface composed of 8×8 grid super units was quickly generated by using the CST-MATLAB co-simulation method,and the electromagnetic simulation results were found to agree with the theoretical results.The results are consistent,and the beams can be scattered evenly,which prove the feasibility of the optimized coding sequence.In conclusion,it is explained that the genetic algorithm can be used to design coding sequences with corresponding application scenarios.