NFC device

• US 20070026826A1
• Filed: 02/24/2006
• Published: 02/01/2007
• Est. Priority Date: 02/24/2005
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Innovision Research & Technology PLC (Broadcom, Inc.)
• Inventors: Wilson, Robin
• Granted Patent: US 8,249,500 B2
• Time in Patent Office: Days
• US Class Current: 455/130
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• 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

Abstract

An NFC device (100) configured at least in part as an integrated circuit, said integrated circuit comprising a controller (107) and a plurality of capacitors (112 to 118), said controller (107) being operable to control one or more of said plurality of capacitors (112 to 118) thereby to vary an operating parameter of said NFC device (100).

Claims

1. An NFC device configured at least in part as an integrated circuit, said integrated circuit comprising a controller and a plurality of capacitors, said controller being operable to control one or more of said plurality of capacitors thereby to vary an operating parameter of said NFC device.

2. An NFC device according to claim 1, comprising a plurality of switches associated with said capacitors, said controller being operable to control said switches to switch one or more of said plurality of capacitors into or out of said integrated circuit thereby to vary an operating parameter of said NFC device.

3. An NFC device according to claim 1, wherein said controller is configured to receive and be responsive to instructions specifying which of said plurality of capacitors should be switched into or out of said integrated circuit to provide a desired variance of said operating parameter.

4. An NFC device according to claim 3, wherein said controller is programmable with said set of instructions at the time of its manufacture.

5. An NFC device according to claim 1, wherein said device is configured as a stand-alone device.

6. An NFC device according to claim 3, wherein said NFC device is configured as a component part of other apparatus.

7. An NFC device according to claim 6, wherein said NFC device is programmable with said set of instructions at the time of the manufacture of said other apparatus.

8. An NFC device according to claim 6, wherein the controller is responsive to receipt of control data or program data from the other apparatus.

9. An NFC device according to claim 1, additionally comprising a magnetic field sensor for sensing a magnetic field strength in the vicinity of said NFC device and generating a sensed field strength signal, said controller being arranged to receive said sensed field strength signal and control one or more of said plurality of capacitors as required to vary said operating parameter.

10. An NFC device according to claim 1, wherein one or more of said plurality of capacitors comprises first and second conductive track portions provided in a common layer of said integrated circuit, said first and second track portions being spaced from one another to form, respectively, first and second electrodes of a capacitor.

11. An NFC device according to claim 10, wherein said first electrode and said second electrode are interleaved one with the other.

12. An NFC device according to claim 11, wherein said first and said second electrodes each include a plurality of transversely extending spaced conducting tabs, said first and second electrodes being arranged such that the tabs of said first electrode are interleaved with the tabs of said second electrode.

13. An NFC device according to claim 10, additionally comprising third and fourth conductive track portions provided in a second common layer of said integrated circuit that is different to the common layer in which said first and second track portions are provided and which is spaced therefrom by an insulating layer, said third and fourth track portions being spaced from one another to form, respectively, first and second electrodes of a second capacitor.

14. An NFC device according to claim 13, wherein said first electrode and said second electrode of said second capacitor are interleaved one with the other.

15. An NFC device according to claim 13, wherein said first and second capacitors are arranged one above the other and electrically coupled in parallel.

16. An NFC device according to claim 13, wherein said first electrode of said first capacitor is coupled to said first electrode of said second capacitor, and said second electrode of said first capacitor is coupled to said second electrode of said second capacitor, said first and second capacitors being arranged one above the other such that laterally extending tabs of said first capacitor overlie laterally extending tabs of said second capacitor second electrode.

17. An NFC device according to claim 1, wherein one or more of said plurality of capacitors comprises an array of capacitors and associated switches, said controller being configured to operate combinations of said switches to switch combinations of associated capacitors into or out of said integrated circuit to thereby improve an operating parameter of said NFC device for tuning said NFC device.

18. An NFC device according to claim 17, wherein said array comprises a binary-weighted array.

19. An NFC device according to claim 17, wherein said switches comprise a transistor or micro-mechanical switch mechanism.

20. An NFC device according to claim 19, wherein said transistor comprises a FET.

21. An NFC device according to claim 1, wherein said operating parameter comprises an induced voltage.

22. An NFC device according to claim 1, wherein said operating parameter comprises an induced current.

23. An NFC device according to claim 10, wherein said conductive track portions are configured to have a depth that is greater than their width.

24. An apparatus comprising an NFC device according to claim 1, said apparatus being selected from a group consisting of a cellphone and a personal digital assistant (PDA).

25. An NFC device comprising, an inductive coupler, a controller and a plurality of capacitors electrically coupled between the inductive coupler and the controller, each said capacitor comprising first and second conductive track portions provided on a common layer of an integrated circuit, said first and second track portions being spaced from another to form, respectively, first and second electrodes of a capacitor, said first electrode and said second electrode being interleaved one with the other, said controller or processor being configured to select a combination of said plurality of capacitors to modify an operating parameter of said NFC device for tuning the NFC device.

26. A method of tuning an NFC device comprising:

providing an NFC device that includes an inductive coupler, a controller, and a plurality of capacitors, and

operating said controller to couple between said coupler and said controller one or more of said capacitors thereby to vary an operating parameter of said NFC device.