The technology and application of free-space power transmission by microwave beam

The point-to-point transfer of power by a microwave beam is an emerging technology with several unique characteristics and applications. The technology is examined in terms of the microwave beam itself, and the conversion technology between microwaves and dc power at either end of the system. The existing efficiencies and the projected efficiencies for the overall system and its elements are emphasized. The procedure for designing a highly efficient microwave beam power transfer system of arbitrary length starting from the microwave generator and terminating with the receiving aperture is given. The potential applications are discussed in terms of the unique characteristics of microwave power transmission. The successful experimental work on microwave-powered helicopters is reviewed. A potential application to bring down power from space is examined.