Nahbereichs

Nahbereichs is a German noun form related to Nahbereich, meaning the near field or a nearby area around a source. In technical usage, Nahbereich denotes the zone close to an emitter or object where the electromagnetic or acoustic field cannot be approximated as a distant, radiating wave. The boundary between Nahbereich and the far field depends on frequency, wavelength, and the size of the source, and is commonly subdivided into the reactive near-field and the radiating near-field (Fresnel region) before reaching the far field (Fraunhofer region).

In antenna theory and instrumentation, understanding the Nahbereich is important for design, measurement, and coupling. Devices placed in the Nahbereich can exchange energy through non-radiative (magnetic or electric) near-field interactions, which is exploited in technologies such as NFC, RFID, and wireless power transfer. Near-field effects also influence shielding, impedance matching, and interference.

In acoustics, the Nahbereich describes regions where sound pressure and particle velocity do not form a plane wave, affecting measurements with probes and the placement of speakers and microphones. In optics, near-field optics studies interactions at scales smaller than the wavelength, including concepts like near-field scanning optical microscopy.

The term Nahbereichs appears in genitive and related contexts in German texts (des Nahbereichs, Nahbereichsgrenze). While the English literature uses near field or near-field region, Nahbereichs is the standard German expression in technical writing and education.