Near field communications, NFC, communicators and NFC communications enabled devices

摘要

A NFC communicator or NFC communications enabled device (100) has a data store (108) to store data, an inductive coupler (102) to couple inductively with the magnetic field of a radio frequency signal and a signal supplier (109) to supply a radio frequency signal to the inductive coupler. A modulator (110) is provided to modulate a radio frequency signal in accordance with data and a demodulator (114) is provided to extract data from a modulated radio frequency signal inductively coupled to the coupler. A controller (107) enables the NFC communicator or NFC communications enabled device both to initiate near field radio frequency communication with another near field RF communicator and to respond to near field radio frequency communication initiated by another near field RF communicator. The inductive coupler (102) has an antenna (120) and a variable impedance element (200) and the controller (107) is operable to control the variable impedance element (200) to control a magnetic field strength associated with a radio frequency signal supplied by the signal supplier.