Research On Sparse Array Antenna Technology

In order to solve the rapidly increasing demands of measurement and control system performance in the future,the large-scale conformal phased array antenna with total airspace coverage,multi-target tracking and high response sensitivity will become the first choice.However,the large number of units and the high complexity of signal processing are disadvantages of large conformal phased array,which bring great challenges to the cost and system sensitivity.A low cost and high-performance system solution is realized by reducing the number of array units by percentage.On the basis of the radiation pattern of conformal array antenna and the sparse optimization algorithm of subarray,this paper analyzes the sparse technique of S-band hemispherical conformal antenna array by subarray division,polyhedral connectome.Firstly,a multi-objective particle swarm optimization algorithm with genetic variation was used to sparse 64 element arrays in spherical region.When the weight was 0.7-0.9 and the c₁/c₂ was 1.25,particle swarm optimization is used to optimize gain and sidelobe level of the sparse array,achieving a 20%sparsity rate and a gain decline value of each scan Angle less than 0.8d B.Meanwhile,the average fitness curve of the particle swarm optimization is better than that of the genetic algorithm under the same condition.Secondly,this paper analyzes and studies the working area,surface form,array layout and array characteristics of the hemispherical conformal array.Based on the method of curved face array sparsity and beam incoming wave direction,the principle of curved face array division based on the optimum fitness is proposed,and the sparse sub-array layer division of hemispheres is determined.In this paper,the normal icosahedral quadratic division is adopted for the hemispherical conformal array,and five different triangular splicing surfaces are obtained.The subarray is extended to the sphere to complete the sparsity of large hemispherical conformal array.Eventually,a spherical conformal array with a sparsity ratio of 24.8%and a two-subsections of the regular icosahedron with a sparsity ratio of 21%were designed.The gain decrease of the three arrays is less than 1d B after sparsity,and the average of the sidelobe is better than-13d B.The results show that the ideal simulation is basically consistent with the curve of the full-wave simulation,and the gain error is less than 0.1d B,which proves the rationality and feasibility of the sparsity method proposed in this paper.