Synthesis Of Sparse Elliptic Ring Array Antenna Based On Modified Generic Algorithm

Array antenna has been widely used in radar,communication,navigation and other fields because of it's characteristics of easy to realize narrow beam,low sidelobe and multi beam.As a special kind of array antenna,sparse array antenna is able to reduce mutual coupling,improve resolution and reduce scanning beam with fewer elements and smaller aperture.The main research content of this thesis is how to optimize the parameter of the array elements to make the peak sidelobe level of the ring array and the elliptical ring array as low as possible under the constraints of the array spacing and the aperture of the array.In this thesis,modified genetic algorithms(MGA)and the dimensionality reduction algorithm are used to optimize the planar sparse array antenna.The main work and innovation points are described as follows:1.The basic theory of array antenna and the principle of directivity diagram product is introduced.Many kinds of linear arrays and planar arrays which are widely used are detailedly analyzed.The formula for calculating their directivity diagram and optimization models are given.2.A traditional generic algorithm is improved into a modified genetic algorithm.Then the improved algorithm is used to optimize sparse ring array antenna.The advantages of the algorithm is that it can not only raise the freedom of the optimization but also reduce the calculation.Compare the simulation result with the existing literature proves that the algotithm is effective.3.Optimize concentric ring arrays by using the radius of the ring as an optimization variable,this method can indirectly optimize the location of the array elements to optimize the array's sidelobe performance.4.The directional characteristics of the elliptical ring array antenna are analyzed.In the case of the same area and the same aperture,the paper research the relationship between the sidelobe performance of the elliptical array and the change of the elliptical centrifugal rate.In the end,a dimension reduction algorithm is proposed to deal with the optimization problem of elliptical ring array.