near field
/nɪə ˈfiːld/Physics
noun
The region close to a radiating source (especially of sound or radio waves), where the variation of the field vector with distance differs from that at large distances.
- The near field is generally taken as extending a distance from the source equal to the wavelength λ, or to 2L 2/λ, where L is the diameter of the source..
Origin
1930s; earliest use found in Wireless Engineer. From near + field.