Lightweight EHF satellites for augmentation of anti-jam communications

Abstract

In an evolutionary EHF anti-jam military satellite communications system, the fundamental service provided by a backbone space segment can be significantly augmented through the use of lightweight EHF satellites or secondary payloads. The use of small EHF satellites to provide this augmentation provides a great deal of flexibility in the deployment and utilization of the space segment assets. In addition, augmentation with small satellites can result in low incremental costs for providing coverage in areas which require some additional capability (e.g.. a crisis region) or for areas with low capacity requirements (e.g.. polar regions). Mobile/survivable launch vehicles with rapid launch preparations provide the option to responsively deploy these small satellites into synchronous altitude circular orbits or into high altitude elliptical orbits (for polar coverage). The communications capabilities provided by these EHF payloads can include both low data rate services (75 to 9600 bps per channel) and medium data rate links (with rates up to -1 Mbps per link) depending on the payload configuration. Through the use of EHF waveform standards, these augmentation satellites will be compatible with existing and planned EHF tenninals. A key payload feature for providing service to small terminals in a theater of operations is a variable beamwidth spot beam antenna which can incorporate autonomous nulling. This type of antenna system can modify its coverage pattern to match changing force deployments and to eliminate interference sources. Lightweight implementations of this type of antenna system. along with other key payload technologies such as high speed, low power digital signal processing subsystems, lightweight frequency hopping synthesizers. and efficient solid-state transmitters, will allow the deployment of significant capabilities in a small augmentation satellite.