Alternate Power Sources for Aerostats

The unique features of microwave power transfer can be harvested for generation of large amounts of electric power thereby eliminating the conventional electric generators needed to operate the systems. This proposal describes the design concepts that will result in very effective and efficient wireless power transfer (WPT) system. Using a large number of internally matched FET devices with high power added efficiency (PAE), an active integrated transmitter antenna array generating (DC to RF) a high power microwave beam will be developed. Such a solid-state transmitter array will also be capable of beam steering in order to keep the beam focused onto a rectenna (mounted to a moving platform) which will be capable of receiving and converting the microwave power into DC power. Beam steering techniques that will either eliminate the conventional phase shifters or minimize their numbers in the phased arrays will be developed to make the WPT system more efficient and effective. A rectenna design approaching 100% (RF to DC) conversion efficiency by retrieving the RF power from the higher order harmonics (generated in the rectifier circuits) will be pursued. Using high power FET devices (PAE exceeding 70%), the WPT systems delivering greater than 60% overall DC to DC conversion efficiency are possible.