Nahfeldartig

Nahfeldartig is a German term that translates to "near-field-like" or "proximity-field-like." It is used in the context of scientific and technical measurements, particularly in acoustics and electromagnetics, to describe a region where the behavior of waves or fields is dominated by the source from which they emanate, rather than by their propagation characteristics over distance.

In acoustics, the near field is the region close to a sound source, such as a loudspeaker. Within this region, the sound pressure and particle velocity are strongly correlated and can vary significantly with position. This contrasts with the far field, where the sound behaves more predictably, with pressure and velocity being in phase and intensity decreasing with the square of the distance. Measurements taken in the nahfeldartig region are therefore influenced by the detailed geometry and motion of the source.

Similarly, in electromagnetics, the near field exists close to an antenna or radiating element. This region exhibits complex field patterns that are highly dependent on the antenna's structure. Further away, in the far field, the electromagnetic radiation propagates as plane waves, with intensity decreasing with the square of the distance. The term nahfeldartig implies that a measurement or observation is being made within this close, source-dependent zone, and that the results will reflect the immediate characteristics of the emitter rather than the ambient wave propagation. Understanding the nahfeldartig region is crucial for accurate characterization of sources and for designing efficient antennas and acoustic systems.