Fraunhofer distance
The Fraunhofer distance, named after Joseph von Fraunhofer, is the value of:
For other articles bearing the name of the physicist, see Fraunhofer.where D is the largest dimension of the radiator (in the case of a magnetic loop antenna, the diameter) and is the wavelength of the radio wave. This distance provides the limit between the near and far field, allowing for 22.5 degrees of phase deviation over the face of the radiator.
