Near-Field Antennas

The Field which is closer to the antenna, is known as near-field. Absorbtion of radiation does not effect the load on the transmitter. Power in this field is continuously radiated and returned back to the antenna.  Near field antenna are strong inductive and capacitive effects from the currents and charges in the antenna that cause electromagnetic components. Radiative near-field is transition of the electromagnetic field from reactive to radiative. Electromagnetic fields radiate when the electric and magnetic fields are perpendicular to each other with zero phase displacement.

Near Field antennas are for short ranges such as retail checkout or  for small spaces and use UHF frequency but their read range is only a few inches.