Spatial modulation using array factor control for smart grid wireless power transmission

A novel spatial modulation method has been proposed for the smart grid wireless power transmission systems. In this method, signals are applied to reflectors placed near antennas of a main power transmission system, and a part of the main beam is modulated by the reflectors, with the minimum influence to the main power beam. The reflector is terminated by a variable impedance device which is controlled by base-band signals. Thus, a directivity including phase shift is modulated. To analyze the system, the array factor theory was used. To demonstrate validity of the proposed method, an experiment using a monopole antenna and a monopole reflector were carried out, where AM modulation index of 6% was observed in a specified direction.