Effective beam forming of phased array antenna for efficient microwave power transmission

Beam forming of the phased array antenna is one of the most important technology in microwave power transmission. Especially in the case of a large-scaled power transmission of long distance, simple beam forming method is required in order to design the outline of the system. In this study, we propose a beam forming method by using synthesized spherical wave. We have been reported that a propagation field with beam waist is obtained by combining the radiating and absorbing spherical waves at the same origin. This propagation field can be used for an efficient power transmission design by arranging the beam waist at the center of the antennas. In this design method, an ideal beam shape is determined first. The phased array antenna is designed in order to represent the ideal beam. The transmission distance with keeping high efficiency can be estimated from the size of the antennas and the beam waist. Because of this simple estimation, we can design the transmission system with good perspective.