Optimum Design of Wireless Power Transmission System Using Microstrip Patch Antenna Arrays

The wireless power transmission (WPT) systems consisting of two microstrip patch antenna arrays at 5.8 GHz are investigated. By maximizing the power transmission efficiency between the two arrays, the optimized phases and amplitudes of the excitations for both the transmitting and the receiving antenna elements can be obtained and then realized by feeding networks. As a demonstration, two WPT systems have been designed and fabricated. One uses a 6 × 6 array as the transmitting and a 4 × 4 array as the receiving, and the measured transmission efficiency reaches 39.4% when the two arrays are separated by a distance of 40 cm. Another one uses 8 × 8 arrays as the transmitting and the receiving, and the measured power transmission efficiency reaches 46.9% when the two arrays are separated by a distance of 100 cm.