Surface Wave Power Transmission Excited on Metal Wires by Capacitive Couplers

Transmission characteristics of electric surface waves, which propagate along a metal wire carrying electric power generated by a capacitive coupler have been studied. Capacitive couplers are wirelessly coupled in the near field, the transmission efficiency drops sharply as the distance increases in the air. On the other hand, by coupling a capacitive coupler to a metal wire and propagating the power radiated from the capacitive coupler as surface waves on the metal wire, the transmission distance can be extended more than one hundred times. The resonant frequency of the coupler considered in this study is 2.45 GHz. Experiments and electromagnetic field simulations were carried out to confirm how the transmission efficiency varies by changing the length, thickness, and material of the metal wire as a guide of the surface wave.