Communication devices having controlled impedances
First Claim
1. A communications device, comprising:
- an inductive coupler configured to couple inductively with a magnetic field of a radio frequency signal;
a feedback circuit including a controlled impedance, the feedback circuit being associated with the inductive coupler; and
a controller configured to adjust the controlled impedance to control a magnetic field strength of the magnetic field of the radio frequency signal.
4 Assignments
0 Petitions
Accused Products
Abstract
A NFC communicator or NFC communications enabled device has a data store to store data, an inductive coupler to couple inductively with the magnetic field of a radio frequency signal and a signal supplier to supply a radio frequency signal to the inductive coupler. A modulator is provided to modulate a radio frequency signal in accordance with data and a demodulator is provided to extract data from a modulated radio frequency signal inductively coupled to the coupler A controller 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 has an antenna and a variable impedance element and the controller is operable to control the variable impedance element to control a magnetic field strength associated with a radio frequency signal supplied by the signal supplier.
26 Citations
37 Claims
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1. A communications device, comprising:
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an inductive coupler configured to couple inductively with a magnetic field of a radio frequency signal; a feedback circuit including a controlled impedance, the feedback circuit being associated with the inductive coupler; and a controller configured to adjust the controlled impedance to control a magnetic field strength of the magnetic field of the radio frequency signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A method for controlling an impedance in a communications device, comprising:
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coupling an inductive coupler with a magnetic field, the inductive coupler being associated with a feedback circuit including a controlled impedance; and adjusting the controlled impedance to control a magnetic field strength of the magnetic field. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
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Specification