ANTENNA SUBSYSTEM
Satellite Communications Glossary
Satellite Communications — Antenna Subsystem
Information on Antenna Subsystem
The antenna subsystem is a critical part of the
spacecraft design. If the spacecraft antenna can be very large,
we do not have to worry about generating so much
power on board to achieve the required power density at
Earth-station antennas. Alternatively, for the same amount of on-board power,
Earth station antennas can be smaller or a higher data
rate can be achieved. Large antennas are difficult to mount,
however, and cause structural problems as they need to be
folded inside the launch vehicle and subsequently deployed in space.
Additionally,
to increase the power density on a particular community of
Earth stations, the satellite must at least be able to
focus its power onto the area occupied by the community,
which requires directionality at least commensurate with the 17.34° angle
subtended by the Earth for a geostationary satellite. In addition
to these Earth-coverage antennas, modern satellites provide a number of
more-focussed beams, either by carrying additional antennas or by sharing
a common dish reflector with feeders offset in some way.
Other topics in our resources on Satellite Communications related to Antenna Subsystem include:
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