Optimal Design of Focused Antenna Arrays

In this paper, we propose an optimal design procedure for the focused antenna array based on the maximization of power transmission efficiency between two antennas. In the optimization process, the focused antenna array to be designed is used as the transmitting antenna and a testing antenna is used as the receiving antenna, positioned in a desired area to be focused. An optimal excitation distribution can thus be obtained for the antenna array to be focused in the desired area. Three 4 × 4 microstrip patch arrays with different focusing distances are designed to validate the optimization technique and demonstrate the focusing capabilities when the antenna array size is fixed. A 6 × 6 microstrip patch array is also built to reveal how the antenna size enhances the focusing effect.