Wireless Communicators

• US 20080194200A1
• Filed: 11/16/2005
• Published: 08/14/2008
• Est. Priority Date: 11/18/2004
• Status: Abandoned Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Innovision Research & Technology PLC (Broadcom, Inc.)
• Inventors: Huomo, Heikki, Symons, Peter, Keen, Ian
• Application Number:
  US11/667,874
• Publication Number:
  US 20080194200A1
• Time in Patent Office: Days
• US Class Current: 455/41.1
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10237 the reader and the record carrier being capable of selectively switching between reader and record carrier appearance, e.g. in near field communication [NFC] devices where the NFC device may function as an RFID reader or as an RFID tag
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: H04B 5/0012 using capacitive coupling
• CPC Class Codes: H04B 5/0043 for taking measurements, e.g. using sensor coils
• CPC Class Codes: H04B 5/0062 in RFID [Radio Frequency Identification] Systems
• CPC Class Codes: H04B 5/0081 with antenna coils loop aerials H01Q7/00
• CPC Class Codes: H04B 5/22 Capacitive coupling
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/73 for taking measurements, e.g. using sensing coils
• CPC Class Codes: H04B 5/77 for interrogation

Abstract

A near field communicator has a driver (6) to supply a drive signal to drive an antenna (10) to generate a magnetic field. A magnetic field sensor (18) is located so as to be within a magnetic field generated by the antenna (6) to sense a magnetic field characteristic. A controller (17) provides a control signal to control the operation of the driver (6) to compensate for any difference between the magnetic field characteristic sensed by the magnetic field sensor (18) and a predetermined parameter.

Claims

1. A near field communicator comprising:

a driver operable to supply a drive signal to drive an antenna to generate a magnetic field;

a magnetic field sensor located so as to be within a magnetic field generated by the antenna to sense a magnetic field characteristic; and

a controller operable to provide a control signal to compensate for any difference between the magnetic field characteristic sensed by the magnetic field sensor and a predetermined parameter.

2. A near field communicator according to claim 1, wherein the characteristic comprises magnetic field strength and the predetermined parameter comprises a parameter representative of a desired magnetic field strength.

3. A near field communicator according to claim 1, wherein the controller comprises a comparator operable to compare a signal representative of the magnetic field characteristic and a signal representative of the predetermined parameter to provide an error signal and a control signal provider operable to provide the control signal to control the operation of the driver in accordance with the error signal.

4. A near field communicator according to claim 1, further comprising a comparator operable to compare a signal representative of the magnetic field characteristic and a signal representative of the predetermined parameter to provide an error signal, wherein the controller is operable to provide the control signal to control the operation of the driver in accordance with the error signal.

5. A near field communicator according to claim 3, wherein the comparator comprises at least one operational amplifier.

6. A near field communicator according to claim 1, wherein the controller is operable to use a signal representative of the magnetic field characteristic and a signal representative of the predetermined parameter to provide proportional, integral and differential signals and to provide the control signal on the basis of the proportional, integral and differential signals.

7. A near field communicator according to claim 1, wherein the controller is operable to provide the control signal using at least one of PID, cascaded PID processes, pre-set software algorithms or fuzzy logic.

8. A near field communicator according to claim 1, wherein the driver is operable to supply an oscillating, for example RF, drive signal to drive the antenna.

9. A near field communicator according to claim 1, wherein the controller is operable to provide as the control signal a signal to control the operation of the driver.

10. A near field communicator according to claim 9, wherein the controller is operable to provide as the control signal a signal to control the level of the drive signal.

11. A near field communicator according to claim 1, wherein the controller is operable to provide as the control signal a signal to control an antenna tuner operable to tune the antenna.

12. A near field communicator according to claim 1, wherein the magnetic field sensor comprises at least one sensor coil.

13. A near field communicator according to claim 1, comprising a receiver operable receive a modulated magnetic field and a demodulator operable to extract modulation from the detected magnetic field.

14. A near field communicator according to claim 13, wherein the receiver comprises the antenna.

15. A near field communicator according to claim 13, wherein the receiver comprises the magnetic field sensor and the controller is operable to detect incoming modulation and to supply the modulated signal to the demodulator.

16. A near field communicator according to claim 13, further comprising a filter operable to filter out modulation from a signal representing the sensed characteristic.

17. A near field communicator according to claim 1, further comprising a modulator operable to modulate the magnetic field generated by the antenna.

18. A near field communicator according to claim 17, wherein the modulator is operable to modulate the magnetic field generated by the antenna in accordance with data to be communicated to another near field communicator.

19. A near field communicator according to claim 1, wherein the controller is operable to increase the level of the drive signal in the event that the sensed magnetic field characteristic is less than the predetermined parameter.

20. A near field communicator according to claim 1, wherein the controller is operable to decrease the level of the drive signal in the event that the sensed magnetic field characteristic is greater than the predetermined parameter.

21. A near field communicator according to claim 1, comprising an RFID tag, an RFID reader or an NFC communicator.

22. A device, system or apparatus having the functionality provided by a near field communicator in accordance with claim 1.