An Efficient Method for Synthesizing Sparse Arrays With Well-Controlled Discrete Array Factors

This paper presents an efficient optimization algorithm for synthesizing the discrete array factor, which extends the optimization domain to the invisible region to mitigate aliasing effect, thereby achieving well-controlled radiation patterns. By further lowering the level of the sidelobes in part of the visible region, the algorithm allows to shape the radiation patterns of sparse arrays with desired characteristics, such as uniform main lobe ripples and low sidelobe levels. Some evanescent modes have been added to compensate for the additional degrees of freedom caused by the increased optimization range, so that the number of the extreme points to be controlled is still approximately equal to the number of degrees of freedom (NDF), maintaining the monotonic convergence property of the algorithm. Numerical examples and FEKO simulation results validate the effectiveness and the accuracy of the proposed method.