Design Considerations for Accurate Beamforming Based on Sparse Antenna Array

The conventional beamforming methods mainly focus on optimizing array factors to fulfill the targeted requirements. It suffers from the limitations of neglecting both the array-element radiation pattern and the mutual coupling in a practical antenna array. In this paper, an iterative synthesis method is introduced for the accurate beamforming of a practical antenna array, and two key techniques are discussed to overcome the limitations. Both the array-element radiation pattern and the mutual coupling are taken into account during the synthesis, contributing to accurate beamforming. To demonstrate the effectiveness of the proposed method, two antenna arrays are experimentally exemplified: a 1×10 sparse patch array with flat-topped beam, and a 1×20 patch array with cosecant-squared beam. Good agreements are achieved between the measured and targeted radiation patterns. The proposed method is promising for beamforming of large-scale antenna arrays.