Research On Optimization Of Sparse Arrays Antenna

How to optimize the sparse distribution of array elements to obtain lower peak side lobe level(PSLL)has always been an important research topic in the field of array antenna synthesis.In this thesis,the sparse planar array is taken as the research object,and the genetic algorithm(GA)is selected to optimize the array element position.Based on the modified genetic algorithm,this thesis studies the adaptive genetic algorithm and the hybrid harmony search genetic algorithm to improve the search performance of the algorithm.The linear array,circular array and rectangular array are sparsely optimized,and the lower peak side lobe level is obtained.The main work of this thesis is as follows:(1)The radiation field of the array antenna is analyzed,and the pattern function of the array antenna is derived.The basic parameters of array antennas are introduced,and the patterns of various common types of linear arrays and planar arrays are simulated.(2)The principle of genetic algorithm is introduced,and a more efficient modified genetic algorithm applied to the optimization of array antenna array is studied.Aiming at the shortcomings of genetic algorithm,the adaptive genetic algorithm which dynamically adjusts genetic operation parameters and the hybrid harmony search genetic algorithm combined with harmony search algorithm are studied.The sparse optimization model of the linear array is established,and the sparse optimization design of the array is carried out using the above algorithm.Comparing the optimization results of each algorithm,it proves the effectiveness of several improved genetic algorithms applied to sparse array optimization,achieving the goal of obtaining a smaller array peak sidelobe level.(3)The pattern function of the circular array is analyzed,and the uniform circular array is simulated.The minimum spacing constraint of the array element is transformed into the optimization variable of the array element angle,thereby reducing the search space.The optimal design of thinned and sparse circular array antennas is carried out,and the array optimization model of circular arrays is deduced.The improved genetic algorithm is used to optimize the array with a given beam direction and the number of array elements,and a lower peak side lobe level is obtained.(4)The rectangular planar array antenna is studied.The pattern function is derived and the sparse optimization model of the rectangular array is established.A twodimensional complex matrix is used to represent the specific coordinates of the array element positions of the rectangular array,and the real and imaginary parts of the complex matrix are designed separately to ensure that the optimized array element positions meet the constraints of the minimum array element spacing.Based on the genetic algorithm and the improved algorithm,the sparse optimization simulation of the rectangular array antenna is carried out,and the goal of reducing the peak sidelobe level of the array is achieved.