SED provided the Feederlink Earth Stations for TerreStar’s Satellite Beam Access Subsystem (SBAS). Under contract to HUGHES, SED designed, developed, procured, assembled, tested, integrated, delivered, installed, and commissioned two Feederlink Earth Stations. Each FES contains banks of IF Channel Units, RF communications equipment, and Telemetry, Tracking, and Command (TT&C) RF equipment, all in fully redundant configurations, in addition to redundant tracking antennas. A Monitor and Control System (MCS) and Uplink Power Control (ULPC) was also provided.
The FES’s key function is to provide the interface between the satellite payload antenna feeds and the GBBF (Ground Based Beam Forming) equipment. The FES equipment handles the Frequency Division Multiplex (FDM) signals in both directions on a transparent basis, and provides the highly reliable phase coherent frequency conversions and high linearity RF amplification. A sophisticated Payload Pilot Receiver developed by SED allows the frequency of the received signals to be adjusted to remove the effects of receive signal Doppler.