Research On Optimization Of Sparse Planar Circular Arrays Antenna

The peak side-lobe level(PSLL)is an important indicator to evaluate the performance of the antenna array.How to reduce the PSLL of the array antenna under the multiple design constraints that the number of elements,the aperture of array and the minimum spacing of element has always been an important research topic.In this thesis,the sparse concentric circular array is selected as the object of study and the modified real genetic algorithm(MGA)is selected as the optimization algorithm to optimize it.According to the difference of element sparsity degree on each auxiliary rings,this thesis proposes a function model to present the relation between ring radius and the degree of sparsity.On the base of MGA,the function model can be embedded into the process of MGA to optimize the sparse concentric circular array,to reduce the PSLL of array antenna.The main contribution and novel of this thesis as follows:1.Introduce the theory of antenna,the theory of synthesis of array antenna pattern,the main parameter of array antenna.Some array antennas are introduced and the radiation pattern is given.2.The basic principle and the main steps of genetic algorithm(GA)are introduced.On the basis of GA,the MGA is introduced.The optimization model of antenna array is derived under the constraints of fixing the aperture,the number of elements and the minimum element spacing.Optimization method of grid ring radii is studied,which selects the ring radii as individual of MGA to optimize the sparse concentric ring array for low PSLL.Contrast with that of other literature,prove the efficient and robust of proposed method.3.According to the difference of element sparsity degree on each auxiliary rings,a function model that present the relation between ring radius and the degree of sparsity is proposed.The function model is Embedded into the process of MGA.to optimize the sparse concentric ring arrays for low PSLL.Contrast with that of other literature,prove the proposed approach can improve the search efficiency and the speed of convergence.4.MGA is applied to optimize the concentric elliptical arrays,the model of optimization of concentric ellipse ring array is inferred.A method that using the principle of calculus to make element uniform distribution on the ellipse ring is proposed.The influence of eccentricity on the elliptic arrays is researched.