A highly efficient and lightweight dual bridge matrix power controller development is proposed that will provide high performance to a solar powered high altitude long endurance (HALE) unmanned air vehicle (UAV), Solar Deck 24-7, that can stay aloft for an indefinite period of time (Goal > 5 years) without fuel. This UAV will be able to hover at altitudes greater than 60,000 feet and perform many of the reconnaissance, communications, and scientific data gathering tasks now performed by geosynchronous satellites at an altitude below low earth orbit thus attaining GEO below LEO. In this Phase I R&D effort, we will define the key requirements and develop the preliminary designs for the dual bridge matrix converter for the UAV application. Simulation models will be developed based on the preliminary design to allow assessment of their performance in the UAV application. . At the end of this Phase I R&D effort, we will have advanced the power controller design to the point where we will be ready to perform detailed design and analysis and build and demonstrate prototype unit during the Phase II effort.