- Alternative form of near field. (in physical acoustics)
- Alternative form of near field. (in radio-frequency electromagnetic technology)
The term has related, but not identical, meanings in various disciplines involving wave behaviour, particularly electromagnetic antennae and acoustics. In general it refers to differences between wave phenomena in regions close to the source, and in regions far from the source. Such differences are of profound importance in various fields of biology, technology, and fundamental research.
(plural near fields)
- (acoustics) The region within a distance a fraction of a wavelength from a sound source. Accordingly, the outer boundary of the near-field region is closer for high-pitched sound than for low-pitched sound.
- (electronics, communication) The region within about half a wavelength from an electrically small antenna . More specifically it is the region within the radiansphere .