Research Of Array Antenna Optimization Algorithm Based On Orbital Angular Momentum

At present,in order to improve the spectrum utilization and wireless channel capacity,the technology of Orbital Angular Momentum(OAM)is introduced into wireless communication.The orthogonality between OAM electromagnetic waves of different modes leads to the breakthrough of the channel capacity of wireless communication system.In this paper,the design of array antenna with OAM and the optimization algorithm is studied.The main work is as follows:First of all,the basic theory of the array antenna with orbital angular momentum is summarized briefly.The principle of orbital angular momentum,the array antenna and the optimization algorithms are introduced.The common examples of antennas generating orbital angular momentum are analyzed.It provides the necessary theoretical support for the follow-up research work.Secondly,based on the principle of linear array antenna and circular array antenna,a cylindrical array antenna radiating beams with OAM is designed,and its electromagnetic simulation and numerical calculation are carried out.The analysis results show that the cylindrical array antenna can radiate the OAM electromagnetic wave well,and has better radiation directivity compared with the circular array antenna.The electromagnetic simulation and numerical calculation results match well.Finally,to solve the problem of the short transmission distance and the difficulty of the receiving antenna design,which are the traditional disadvantages of OAM array antenna,two methods are introduced to optimize the cylindrical array antenna.One is to use the genetic algorithm to optimize the amplitude and the phase of the current excitation of the cylindrical array antenna.Considering the shortcomings of genetic algorithm,we propose another improved method to reduce the number of parameters to be optimized.At the same time,the maximum radiation direction and the directivity are analyzed to achieve the optimization.