parabolic antenna

An antenna comprising a parabolic reflector with a transmitting and receiving ele-

ment positioned at or near its focal point. The parabolic reflector is made of a reflective material, usually metal, and is shaped like a parabola, which looks much like a cross-section of a bowl. A parabolic reflector shapes a transmitted radio signal, focusing it into a collimated beam, with increased power density, or signal strength. Similarly, the reflector gathers an incoming signal and focuses it on the receiving element with greater intensity, i.e., gain.A fully circular parabola, or paraboloid, is a three-dimensional parabola that looks much like a shallow bowl. A paraboloid antenna shapes a radio signal much as the mirror in a flashlight shapes an optical signal. Paraboloid antennas are used on satellites to create spot beams. See also collimation, gain, satellite, and spot beam.

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