Mapping-Based Optimization Method for Pattern Synthesis via Array Element Rotation

Abstract

This article presents a mapping-based optimization method for pattern synthesis via array element rotation. The optimization is carried out through optimizing the orientation of each array element to minimize the sidelobe and cross-polar level while maximizing the co-polar level of the main beam in a desired direction. The basic idea of the proposed method is to convert a variable definition domain problem into a fixed definition domain problem through coordinate transformation. Based on this, the optimization is well integrated with the method of moments (MoM), and it is convenient to calculate the radiation pattern properties and their sensitivities with respect to the design variables. Thus, the design optimization problem can be efficiently solved by use of any gradient-based algorithm. Additionally, benefiting from the combination of the mapping transformation and the full-wave MoM simulation, the mutual coupling between array elements is rigorously taken into account and the complex meshing of the surrounding radiation region is avoided. Furthermore, the change in the array performance is derived only associating with the transformation variables, thus remeshing for iteratively changed arrangements is avoided and the computing cost is saved. Typical numerical examples are provided to validate the effectiveness of the proposed method.