Radiation pattern

Common card · No. 450507

An antenna radiation pattern (or antenna pattern or far-field pattern) is the directional (angular) dependence of the field strength (sometimes also the phase) of the radio waves from the antenna or other source. Particularly in the fields of fiber optics, lasers, and integrated optics, the term radiation pattern may also be used as a synonym for the near-field pattern or Fresnel pattern. This refers to the positional dependence of the electromagnetic field in the near field, or Fresnel region of the source. The near-field pattern is most commonly defined over a plane placed in front of the source, or over a cylindrical or spherical surface enclosing it. The far-field pattern of an antenna may be determined experimentally at an antenna range, or alternatively, the near-field pattern may be found using a near-field scanner, and the radiation pattern deduced from it by computation. The far-field radiation pattern can also be calculated from the antenna shape by computer programs such as NEC...

Read on Wikipedia · Image James Wlodarczyk (--catslash 23:44, 31 July 2006 (UTC)), Public domain