fan beam

fan beam

See antenna.

fan beam

[′fan ‚bēm] (electromagnetism) A radio beam having an elliptically shaped cross section in which the ratio of the major to the minor axis usually exceeds 3 to 1; the beam is broad in the vertical plane and narrow in the horizontal plane. A radar beam having the shape of a fan.

fan beam

fan beamPencil-beam antenna pattern.fan beamFan-beam antenna pattern.A fan-shaped radar beam, broad in the vertical plane and narrow in the horizontal plane. A fan beam allows only the measurement of the azimuth angle. Typically, a fan beam in aircraft surveillance radar is 1° to 2° in azimuth and 20° to 40°, or broader, in elevation.