Fast Computation Of Gain Patterns For Phased Array Antennas And Subarray Technique

Phased array antennas,due to their ability to flexibly control the excitation amplitude and phase of each antenna element,have been widely used for focusing,scanning,shaping,and agility in comprehensive electronic information systems.However,as various carrier platforms become increasingly complex in electromagnetic environments and require higher performance,the size of phased array antenna elements has continued to increase.However,the expansion of the array element size brings challenges,such as difficulty in accurately obtaining the Active Element Pattern(AEP)and a sharp increase in the number of RF channels.Meanwhile,traditional pattern computation and synthesis methods often cannot directly obtain the value of gain,and low sidelobe and high gain are often difficult to achieve simultaneously.Therefore,this thesis focuses on the fast computation and synthesis methods of phased array gain patterns,and conducts in-depth research on the optimization of heterogeneous edge-subarray technology to suppress the sidelobe of one-dimensional active phased arrays without losing Effective Isotropic Radiated Power(EIRP),and reduce the number of RF channels.It should be noted that the gain discussed in this thesis is the realized gain.The research content and results of this thesis are as follows:1.Fast computation of phased array gain patterns.First,the mathematical expression of the phased array gain pattern is derived.Then,the rotation of representative elements(including rotation,translation,projection,and 2D interpolation)is used in combination with region partitioning techniques to achieve rapid acquisition of the Active Element Patterns of any array.Finally,the vector gain pattern of any array is derived.To verify the accuracy of the proposed algorithm,an 80-element irregular array model was established,and the numerical simulation results were found to be in good agreement with the fullwave simulation results.2.Maximum gain beamshaping synthesis of array antennas with sidelobe constraints.First,the theoretical limit solutions for maximum gain and maximum directivity under unconstrained conditions are investigated,and it is verified through simulation examples that maximum directivity does not necessarily lead to maximum gain.Then,a convex optimization-based algorithm for maximum gain with sidelobe constraints is studied,and non-convex problems are transformed into convex ones using convex relaxation or iterative perturbation approximation techniques,and are compared with optimal directivity through simulation examples.Finally,a beamshaping algorithm for maximum power coverage is studied,and the minimum gain value of the power coverage area is maximized using Sequential Quadratic Programming(SQP),and simulation examples are used to verify the algorithm.3.Sidelobe reduction for uniformly excited phased antenna arrays employing optimized heterogeneous edge-subarray technique.First,to address the trade-off between EIRP and sidelobe,a phased array architecture based on heterogeneous edge-subarray is proposed.Then,a two-step iterative convex optimization approach is used to optimize the embedded amplitude and phase of the heterogeneous edge subarrays,achieving equal channel power and side lobe suppression in active phased arrays.Next,the proposed algorithm is compared with existing algorithms using three different array models in various application scenarios to demonstrate its superiority and robustness.A 14-element dual-polarized crossed dipole linear array is fabricated,and the test results are in good agreement with full-wave simulations.