thumb|right|upright=1.4|Three-dimensional antenna radiation patterns. The radial distance from the origin in any direction represents the strength of radiation emitted in that direction. The top shows the [[Directional antenna|directive pattern of a horn antenna, the bottom shows the omnidirectional pattern of a simple vertical dipole antenna.]]
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.
See also
- Antenna modeling
- E-plane and H-plane
- Vertical and horizontal (radio propagation)