• A parabolic dish (in the shape of a parabola) will reflect all radio waves that enter the dish into a single point, called the focus
• A feed/receiving horn, built around this focus, gathers signals reflected to it so that they can be processed by the internal computer

• The feed/receiving horn also sends signals from the satellite; these signals are reflected off dish and sent down to Earth
• The feed/receiving horn can also be offset from dish, so that it will not block any incoming signals

• Another option is to use another, smaller parabolic dish within the larger dish; this is more compact, but also more complicated

• Dish antennas are usually large, but they are the most efficient means of reflecting signals
• This means that they are unnecessary for satellites which will be close to the Earth, but very useful for satellites going far off into space
• Dish antennas are very durable and moderately expensive

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Produced by Galactics.
Comments: galactics@spacesim.org.
Last updated on: 8 August 1997.