John R. Juroshek

Abstract: The solar power satellite (SPS) is a concept for generating electrical power from solar energy via a geosynchronous orbiting satellite. A facility, such as this, would be able to send approximately 5 to 10 gigawatts of power to earth on a highly focused 2450 MHz microwave beam. The electromagnetic compatibility problems cause by this amount of microwave power transmission are recognized as a critical factor in the implementation of such a system. This report examines the potential for interference between SPS and conventional satellite earth terminals. The report begins with a general discussion of the different ways that interference between SPS and satellite systems can occur. Estimates are made of the levels of harmonics and out-of-band noise that are likely to be radiated by SPS. These levels are then compared to the interference threshold for various representative satellite scenarios. The report concludes that a potential for interference exists in the 2500 MHz to 2690 MHz direct broadcast satellite frequency assignments. Another potential problem is SPS radiation at the 7350 MHz 3d harmonic that falls within the 7300 MHz to 7400 MHz space-to-earth government satellite band.

Keywords: interference; solar power satellite; satellite

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

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