Development of a kW class microwave wireless power supply system to a vehicle roof

We first have introduced a microwave wireless power supply system charging electric vehicles and described transmitting antennas suitable for the system. The aim of this paper is partly to find out the performance limit of a single antenna, instead of an array antenna. Five kinds of antennas have been designed and simulated on Ansoft HFSS in order to examine their usefulness as a candidate for transmittion: a rectangular horn, followed by a rectangular horn loading an E plane metal-plate lens, a conical horn loading a dielectric lens, a corrugated horn, and a corrugated horn loading a dielectric lens. We have confirmed that a higher directivity can be achieved when antennas are loading a metal lens or a dielectric lens. In such cases, however, the scattering occurs, even if the reflection coefficient is very low. Further improvement still needs to be done in future.