Research On High Precision Array Antenna Beamforming And Algorithms

With the rapid development of communication,vehicle networking,electronic countermeasures and radar systems,the requirements for antenna performance are getting higher and higher.Compared with single antenna,array antenna can achieve more functions.In different application scenarios,the antenna can have different directivity by beamforming technology.However,as the appearance of large-scale array antennas,the antenna gradually tends to miniaturize,and the coupling effect between the array elements is getting worse.In this thesis,the influence of decoupling structure design and beamforming algorithm is studied.The main works are as follows:1.A hybrid decoupling structure based on band-stop filtering characteristics is designed.Using the defect ground structure and the dielectric plate wall structure for decoupling treatment,the isolation degree between antenna elements is greatly improved in the application of binary microstrip patch antenna,and its S₁₂ parameter reaches-77d B,and the structure is applied to the beamforming of 1×8 array antenna.2.An enhanced adaptive cat swarm algorithm is proposed.Based on the cat swarm algorithm,its basic parameters can change adaptively according to the number of iterations and the value of the fitness function.In addition,a strategy combining roulette and elite selection is added to the search mode to increase the population diversity.A comparative analysis of the performance of various intelligent optimisation algorithms shows that the adaptive cat swarm algorithm has the ability of fast convergence and global optimization.3.Based on adaptive cat swarm algorithm and hybrid decoupling structure,multi-target beamforming of array antenna is carried out.In this thesis,the eigen excitation method is used to perform high-precision multi-target beamforming for the array antenna with hybrid decoupling structure based on the joint call of Matlab and HFSS.The simulation results show that the excitation amplitude and phase of the array elements meet the target design requirements of beamforming.4.High precision multi-target beamforming is verified.In order to further illustrate the simulation accuracy of beamforming,the accuracy of the following three kinds of beamforming methods are compared and verified:beamforming without considering mutual coupling effect,beamforming with only eigen excitation method,and beamforming with decoupling structure and eigen excitation method to further reduce coupling effect.The results show that the proposed method is better than the other two methods.