Antenna unit with automatic tuning

摘要

An antenna unit provided with an antenna which comprises at least one turn, wherein the antenna unit is further provided with an electronic circuit which is connected with the antenna, wherein the electronic circuit comprises connection contacts for connecting the antenna unit with a transmitting device, wherein the electronic circuit is arranged to draw energy from a transmission signal which is supplied to the connection contacts and, utilizing this energy, to tune the antenna unit such that this antenna unit has an impedance which has at least substantially no imaginary component in use of the transmission signal concerned.