Near field RF communicators and near field RF communications enabled devices

• US 8,140,010 B2
• Filed: 10/12/2007
• Issued: 03/20/2012
• Est. Priority Date: 10/24/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Innovision Research & Technology PLC (Broadcom, Inc.)
• Inventors: Huomo, Heikki, Symons, Peter R.
• Primary Examiner(s): Donovan, Lincoln
• Assistant Examiner(s): Chen, Sibin
• Application Number:
  US12/446,591
• Publication Number:
  US 20100015917A1
• Time in Patent Office: 1,621 Days
• Field of Search: None
• US Class Current: 455/41.1
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A near field RF communicator (100) has an inductive coupler (102) and a first signal provider (109, 110, 111) to cause the inductive coupler to provide a first signal that when inductively coupled to the inductive coupler of another near field RF communicator in near field range is insufficient to cause initiation of communication with that other near field RF communicator. A sensor (116) senses a change in an impedance of the inductive coupler (102) due to inductive coupling of the first signal between the inductive couplers of the said near field RF communicator and a said other near field RF communicator in near field range. A controller (107) determines whether or not another near field RF communicator is in near field range on the basis of any change in impedance sensed by the sensor and, if another near field RF communicator is determined to be in near field range, causes a second signal to be inductively coupled to the other near field RF communicator to initiate communication between the two near field RF communicators. The sensor may use a phase detector (118) to enable a change in impedance to be sensed by detecting a change in a current-voltage phase relationship resulting from a change in impedance.

Claims

1. A near field RF communicator for initiating communication with a second near field RF communicator, the near field RF communicator comprising:

a first inductive coupler operable to couple inductively to a second inductive coupler included within the second near field RF communicator in near field range;

a first signal provider operable to cause the first inductive coupler to provide a first signal to the second near field RF communicator, wherein the first signal is insufficient to cause initiation of communication with the second near field RF communicator;

a sensor operable to sense a change in an impedance of the first inductive coupler due to inductive coupling between the first inductive coupler and the second inductive coupler;

a determiner operable to determine whether the second near field RF communicator is in near field range on a basis of any change in the impedance of the first inductive coupler sensed by the sensor; and

an activation signal provider operable, in response to the determiner determining that the second near field RF communicator is in near field range, to supply a second signal to initiate communication between the near field RF communicator and the second near field RF communicator,

wherein the first signal provider and the activation signal provider are different signal providers.

2. A near field RF communicator according to claim 1, wherein the first signal provider and the activation signal provider are operable to supply the first and second signals such that the first signal is of lower power than the second signal.

3. A near field RF communicator according to claim 1, wherein the first signal provider and the activation signal provider are operable to supply the first and second signals such that the first signal comprises signal bursts.

4. A near field RF communicator according to claim 1, wherein the first signal provider and the activation signal provider are operable to supply the first and second signals such that the first signal is of lower amplitude than the second signal.

5. A near field RF communicator according to claim 1, wherein the first signal provider and the activation signal provider are operable to supply the first and second signals such that the first and second signals are of different frequencies.

6. A near field RF communicator according to claim 1, wherein the first signal provider and the activation signal provider comprise a single signal provider.

7. A near field RF communicator according to claim 1, wherein the first and second signals comprise different modes of the same signal.

8. A near field RF communicator according to claim 1, wherein the activation signal provider is operable to supply the second signal to the first inductive coupler.

9. A near field RF communicator according claim 1, wherein the activation signal provider is operable to supply the second signal to the second inductive coupler, included within the second near field RF communicator, wherein the second inductive coupler is separate from the first inductive coupler.

10. A near field RF communicator according to claim 1, wherein the sensor is operable to sense a change in impedance by detecting a difference in phase between a current through and a voltage of the first inductive coupler.

11. A near field RF communicator according to claim 1, wherein the near field RF communicator is battery-powered, an NFC communicator, an RFID reader, RFID transceiver, or operable under ISO/IEC 18092 or ISO/IEC 21481.

12. A near field RF communicator according to claim 1, wherein the near field RF communicator is provided within an attachable housing, a housing portion, in an access card, or a housing resembling a smart card.

13. An electrical device comprising a near field RF communicator according to claim 1, wherein the near field RF communicator is integrated within the functionality of the electrical device and includes at least one integrated circuit within the electrical device and wherein the electrical device includes a user interface for enabling a user to input instructions to control an operation of the near field RF communicator.

14. An electrical device according to claim 13, wherein the device comprises at least one of a mobile telephone, a portable computing device such as a personal digital assistant, notebook, or lap-top, a personal or desk top computer, a computer peripheral such as a printer, or other electrical device such as a portable audio and/or video player.

15. A portable communications device incorporating a near field RF communicator according to claim 1.

16. A near field RF communicator according to claim 1, wherein the first signal is created by controlling the first signal provider to switch ON and OFF a signal generator in accordance with data to be communicated.

17. A near field RF communicator for initiating communication with a second near field RF communicator, the near field RF communicator comprising:

a sense antenna operable to couple inductively with an antenna of the second near field RF communicator;

an RF signal provider operable to cause the sense antenna to provide a first signal to the second near field RF communicator, wherein the first signal is insufficient to cause initiation of communication with the second near field RF communicator;

a detector operable to provide a detection signal indicative of a change in a phase relationship between a current through and a voltage of the sense antenna, wherein the change in the phase relationship results from a mutual inductive coupling of the first signal between the sense antenna and the antenna of the second near field RF communicator in near field range; and

a controller operable to determine when the second near field RF communicator is in near field range by receiving detection signal from the detector, wherein the detection signal is indicative of the presence of the second near field RF communicator, and wherein the controller is further operable to control the RF signal provider to cause a second signal to be inductively coupled to the second near field RF communicator in near field range, wherein the second signal initiates communication with the second near field RF communicator, and wherein the detector is positioned outside of the controller.

18. A near field RF communicator according to claim 17, further comprising a signal controller operable to provide the first signal by interrupting an oscillating signal to provide bursts of the oscillating signal.

19. A near field RF communicator according to claim 17, wherein the RF signal provider causes the sense antenna to function as both the sense antenna and as a communication antenna, by instructing the sense antenna to produce the second signal.

20. A near field RF communicator operable to act as an initiator to initiate communication with a target near field RF communicator, the initiator being operable in a power saving sense mode, to provide a first signal that enables the initiator to sense the presence of the target near field RF communicator when in near field range without initiating communication with the target near field RF communicator, and in a communication initiation mode in which the initiator is operable to provide a second signal to cause initiation of communication between the target near field RF communicator and the initiator, the initiator being operable to sense a change in an impedance resulting from the presence of the target near field RF communicator in near field range and to switch from the power saving sense mode to the communication initiation mode in response to such a change in the impedance, wherein the near field RF communicator provides the first signal while in the power saving sense mode and before the near field RF communicator switches from the power saving sense mode into any other mode.