Research On Antenna Array Arrangement And Beam Optimization Technology

The peak sidelobe level of the beam pattern is a vital performance index in signal processing.It is often desirable to obtain as low a sidelobe level as possible to achieve effective interference rejection.The ways to control the sidelobe level are mainly divided into two categories: one is achieved by placing the geometric position of the array reasonably,and the other is by adjusting the weighting coefficients of the array.The former type of problem belongs to the array optimization arrangement,and the latter type belongs to the beam optimization control.How to find the optimal array distribution under specific constraints and the corresponding optimal weighting coefficient to control the sidelobe level to the desired level is the core of the study in the thesis.This thesis mainly covers the following research contents:1.Two common array optimization methods and two classical beam optimization algorithms are introduced while simulation experiments and performance analysis of each algorithm are carried out respectively.2.Genetic algorithm is applied to optimizing array arrangement for three different complex antenna arrays,including sub-array linear array,sub-array plane array with misalignment structure and real terrain super-large scale sparse array.Firstly,according to the geometry and constraints of the array,the appropriate optimization model is established,based on which different targeted algorithm operations are designed,and the effectiveness of the array method is verified by simulation experiments.Especially for the sub-array plane array with misalignment structure,an array optimization method on the basis of random circular grid is developed,which can improve the optimization effect by expanding the search space of the algorithm.3.The beam optimization method is studied for the scene where the sidelobe level is still unable to meet the requirements after array optimization.This thesis mainly studies the relationship between the weighting coefficient and the power response at a specific angle in the beam pattern.Firstly,a single-point accurate response control algorithm based on adaptive theory is introduced,and simulation experiments illustrate the advantages and disadvantages of the algorithm.On this basis,a single-point accurate response control algorithm based on sidelobe cancellation principle is developed,which can not only achieve flexible and accurate single-point response control but also reduce the complexity of finding the optimal solution to the problem.4.In order to overcome the high iteration time consumption of the single-point accurate response control algorithm when there are a large number of points in the beam pattern to be adjusted,the principle of multi-point coarse response control based on genetic algorithm is discussed firstly,which leads to the optimization idea of multi-point response control.Then based on the single-point accurate response control algorithm,a two-point response control algorithm that can achieve response control at two angles in one iteration is extended and a more efficient multi-point accurate response control algorithm is studied.Experimental simulations verify and illustrate the performance of all the algorithms above.