Research On Design And Beamforming Of Phased Array Radar With Displaced Subarray

Phased array radar is widely used due to its excellent beam forming ability and flexible beam direction,and it has played an important role in early warning detection,air defense and antimissile,space surveillance and other fields.In recent years,with the continuous expansion of radar application fields and scenarios,radar equipment has shown a trend of large-scale and fully digitalized development.Regardless of whether it is large-scale or fully digitalized,it is hoped that the radar has a lower engineering cost.Therefore,the cost control problem of phased array radar has become more and more prominent,and it has become one of the hot issues in the academic and industrial circles.Displacement subarray technology is a low-cost phased array technology that can reduce costs while having a wide scanning range.The dislocation subarray technology reduces the number of cells by increasing the cell spacing,thereby reducing costs,and suppresses the grating lobes through random subarray dislocation.However,the dislocation subarray technology still faces many problems in theory and practice,including the low efficiency of the design algorithm and the inability of the design scheme to closely meet the actual needs of the project.The thesis takes the dislocation subarray design and beam forming as the starting point,and is committed to solving the above-mentioned theoretical and engineering problems faced by the dislocation subarray technology.The results of the thesis include the following aspects:(1)Optimization method of dislocation subarray.The optimization problem of misplaced subarrays is a complex non-convex optimization problem,and it is difficult to optimize.First,the method in the literature was reproduced,and the optimal grid selection based on the grid division method was obtained.Aiming at the low efficiency of the algorithm in the existing literature,an iterative convex optimization method that can quickly obtain the quasi-optimal solution for small fronts and row subarrays is proposed;the existing algorithms in the existing literature are not suitable for large fronts.,An adaptive gradient algorithm is proposed,which can obtain sub-optimal solutions with high computational efficiency for arrays of any size and shape.Finally,through the comparison of the results,the effectiveness of the algorithm is verified.(2)Modular dislocation subarray design scheme.Although the dislocation subarray design adopts the idea of modular subarray,the front panel used to install the subarray module is still non-modular: the front panels of different radars are completely inconsistent.In response to this problem,a modular design scheme for dislocation subarrays was proposed.By designing only one basic module and rotating and splicing to form an array,it is not necessary to make independent panels;an optimization model for this problem was established,and a discrete variable-based The adaptive gradient algorithm is improved,and the sub-optimal solutions under different apertures are obtained;the influence of the subarray structure on the result is analyzed,and the influence of the subarray structure on the design result is verified by the circular array and the sparse array: whether the subarray is sparse or not It will affect the grating lobe suppression effect,but will increase the average side lobe level;finally,the scalability of the design is analyzed.The results show that the design method has high scalability,and different fronts can use the same panel structure.(3)Four-quadrant single pulse dislocation subarray design.Aiming at the commonly used four-quadrant symmetrical single-pulse angle measurement application,a design scheme of the staggered subarray for this application is proposed.First,optimize modeling and establish an optimization model under a symmetric structure;then use an improved adaptive gradient algorithm based on the symmetric structure to optimize it;analyze the distortion of the single pulse curve caused by the dislocation of the super subarray;Single pulse formation technology in the case of array misalignment.Finally,a comparison with the results in the literature verifies the superiority of the proposed scheme.