Radio engineering. The region where the distance from a radiating antenna is less than the wavelength of the radiated EMF. Compared to the far field, the electric and magnetic fields of the near do not have a substantially plane-wave character, but vary considerably from point to point. A simple conversion of the field components electric field strength (E), magnetic field strength (H), and power density (S) is not possible.
The SAR value is the only reasonable exposure measure in the near field.