Near-Field Focus Radiation from Phased Antenna Array for Best Reception by Relatively Large Antennas

This paper examines the behavior of near-field focus (NFF) radiation of a transmitting antenna (TXA) array for an enhanced power transfer to a relatively large receiving antenna (RXA). In addition to the conventional consideration of focusing power intensity, the phase behavior is also examined. It is discovered that the power transfer effectiveness of NFF radiation to RXAs highly depends on the size of RXA and the phase behavior of the TXA's NF distribution. Based on the examination of the reaction equation between the TXA and RXA, the maximum power transfer results in a concept of conformal phase matching between the TXA and RXA's co-polarized components of radiation. This new type of NFF antenna design is more general, and can be referred to a conformal NFF antenna (CNFFA) design.