Funkfeldern

Funkfeldern is a term used in German-language discussions to refer to the spatial distribution of radio-frequency electromagnetic fields generated by sources such as antennas and transmitters. In radio engineering, the concept describes how electric and magnetic field components vary with position and direction and how these fields interact with receivers. The electromagnetic field is described by Maxwell's equations, and discussions distinguish near-field and far-field regions.

Near-field includes reactive and radiating near-field; the boundary to the far-field is often given by distance greater than 2D^2/λ, where D is the largest dimension of the source and λ is the wavelength. In the far-field, the field pattern stabilizes and the radiated power falls roughly as 1/r.

Applications include antenna design, coverage planning for mobile and broadcast networks, radar, and electromagnetic compatibility testing. The concept also underpins field-strength mapping and link-budget calculations for wireless communication.

Measurement and regulation: Field strength is usually expressed in volts per meter for the electric field, and instruments such as field-strength meters and calibrated antennas are used. Regulatory guidelines, for example from ICNIRP or FCC, specify exposure limits and testing procedures related to Funkfeldern in public environments.

Historically, the concept arises from Maxwell's equations and the development of radio technology in the 20th century and remains central to wireless engineering and RF safety assessments.