Research On Antenna Array Design And Adaptive Beamforming Technology Of Missile Borne Conformal Array

Conformal array antenna has the advantages of low profile,small volume and easy system integration.Installing conformal array in radar seeker not only has good aerodynamic performance,but also can effectively reduce the radar cross-sectional area,so that the radar has low detectability.The research on conformal array antenna design and beamforming technology is in line with the application background and future development direction of the integration of reconnaissance,interception and detection.It is the key way and important research content of the development of phased array radar technology.In this paper,the design of missile borne conformal array and the research of adaptive beamforming technology are carried out to realize the target search and angle tracking of radar seeker.It is mainly divided into the following three aspects:1.Research on the optimal design of conformal array.Firstly,the conical conformal array is modeled,and the geometric structure,occlusion effect and antenna pattern difference of each array element are considered.In the range of common projectile diameter,for the typical uniform conical conformal array model,this paper proposes a sparse optimal array arrangement method suitable for conical conformal array based on genetic algorithm.According to the geometric structure characteristics of conical conformal array,this method designs the array element selection matrix,and reduces the sparse optimal array arrangement problem of conical conformal array from three-dimensional array to two-dimensional array.Simulation results show that compared with random sparse conical conformal array,the pattern of sparse conical conformal array designed in this paper has lower sidelobe level under the same sparsity rate.2.Research on conformal array adaptive beamforming technology.Firstly,the principles of adaptive beamforming and adaptive sum and difference beamforming are introduced.Considering that the number of sparse conical conformal array elements is still large and the adaptive processing dimension of array element level is large,the sub array division methods of conformal array are analyzed,and the beamforming performance of sparse conical conformal array under different sub array division methods is studied.Finally,the adaptive sum and difference beamforming technology of subarray sparse conical conformal array is studied,and the performance of adaptive sum difference beamforming under different beam directions and the anti-interference performance of subarray sparse conical conformal array under different interference numbers and positions are analyzed.The analysis shows that the subarray sparse conical conformal array can reduce the adaptive processing dimension,reduce the system complexity,and have good anti-interference performance.3.Research on conformal array adaptive monopulse angle measurement technology.Adaptive monopulse angle measurement technology can suppress interference and measure the angle of the target at the same time.However,when the number of interference is large or the interference is near the main beam,the null of adaptive beamforming will cause the distortion of the main beam of sum and difference beam,resulting in the larger error of traditional adaptive monopulse angle measurement.In this paper,the constrained adaptive monopulse angle measurement method is studied.This method realizes the shape preservation of the main beam by imposing constraints on the main beam,which is conducive to ensuring the performance of sum and difference monopulse angle measurement,but the additional constraints will consume the spatial degree of freedom of the system.To solve this problem,this paper further studies the conformal array generalized adaptive monopulse angle measurement method.In this method,the adaptive monopulse ratio is solved,and the slope correction matrix and deviation correction are used for linear compensation,so as to solve the target angle.This method does not depend on the slope of the monopulse ratio curve obtained from the sum and difference beam pattern,nor does it lose spatial freedom.In this paper,when solving the slope correction matrix of subarray sparse conical conformal array,the occlusion effect and the difference of antenna pattern of each array element are taken into account.The simulation analysis under different interference number and position shows that with the increase of interference number or when the interference position is close to the main beam position,compared with the traditional adaptive monopulse angle measurement method at subarray level and the constrained adaptive monopulse angle measurement method at subarray level,the generalized adaptive monopulse angle measurement method at subarray level has better angle measurement performance and can suppress the interference.