Near field communication device

• US 10,110,281 B2
• Filed: 03/17/2017
• Issued: 10/23/2018
• Est. Priority Date: 03/17/2017
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Ding, Jingfeng, Al-kadi, Ghiath, Merlin, Erich
• Primary Examiner(s): Vo, Nguyen
• Application Number:
  US15/462,771
• Publication Number:
  US 20180269929A1
• Time in Patent Office: 585 Days
• CPC Class Codes: G06K 7/10168 the powering being adversely affected by environmental influences, e.g. unwanted energy loss in the interrogation signal due to metallic or capacitive objects in the proximity of the interrogation device or in the proximity of the interrogated record carrier
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/75 for isolation purposes
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication

Abstract

A near field communication (NFC) device capable of operating by being powered by the field includes an NFC module for generating an electromagnetic carrier signal and modulating the carrier signal according to data to be transmitted, and an antenna circuit coupled to and driven by said NFC module with the modulated carrier signal. An electromagnetic compatibility (EMC) filter of the NFC device is coupled to the NFC module via output terminals of said NFC module. A powered by the field circuit of the NFC device is adapted to harvest energy from an external field to power said NFC device. The power by the field circuit is coupled to said EMC filter via one or more impedance elements. The NFC device is adapted to be able to operate in one of a reader mode, a battery supplied card mode, and a powered by the field card mode.

Claims

1. A device for contactless communication comprising:

an NFC module being adapted to generate an electromagnetic carrier signal and to modulate the carrier signal according to data to be transmitted;

an electromagnetic compatibility (EMC) filter coupled to said NFC module via output terminals of said NFC module; and

an antenna circuit coupled to and driven by said NFC module with the modulated carrier signal;

said NFC module including a powered by the field (PBF) circuit adapted to harvest energy from an external field to power said device;

said powered by the field circuit having a first terminal coupled to a first terminal of said EMC filter via a first impedance block and a second terminal coupled to a second terminal of said EMC filter via a second impedance block;

wherein said first impedance block includes a first impedance element internal to the NFC module and a second impedance element external to the NFC module, said first and second impedance elements being arranged in series;

wherein said second impedance block includes a third impedance element internal to the NFC module and a fourth impedance element external to the NFC module, said third and fourth impedance elements being arranged in series;

said device being adapted to be able to operate in a powered by the field card mode.

2. The device of claim 1,

wherein said first impedance element is further coupled to a first switch, said first impedance and said first switch being arranged in parallel;

and

wherein said third impedance element is further coupled to a second switch, said third impedance element and said second switch being arranged in parallel.

3. The device of claim 2, wherein said first and second switches are configured to be closed when said device operates in the powered by the field card mode.

4. The device of claim 2, wherein said first and second switches are configured to be open when said device operates in a reader mode.

5. The device of claim 1, wherein said antenna circuit is a single-end antenna.

6. The device of claim 5, further comprising a balanced to unbalanced (Balun) transformer coupled between the EMC filter and the antenna circuit.

7. The device of claim 1, wherein said antenna circuit is a differential antenna.

8. The device of claim 1, wherein said device is incorporated in a mobile device and adapted to be powered by the mobile device.

9. The device of claim 1, wherein said device is adapted to be able to operate in a reader mode.

10. The device of claim 1, wherein said device is adapted to perform active load modulation (ALM) in a card mode.

11. The device of claim 1, wherein said device is adapted to perform passive load modulation (PLM) in the powered by the field card mode.

12. The device of claim 1, wherein the device is an NFC device.

13. A device for contactless communication comprising:

an NFC module being adapted to generate an electromagnetic carrier signal and to modulate the carrier signal according to data to be transmitted;

an electromagnetic compatibility (EMC) filter coupled to said NFC module via output terminals of said NFC module; and

an antenna circuit coupled to and driven by said NFC module with the modulated carrier signal;

said NFC module including a powered by the field (PBF) circuit adapted to harvest energy from an external field to power said device;

said powered by the field circuit having a first terminal coupled to a first terminal of said EMC filter via a first impedance block and a second terminal coupled to a second terminal of said EMC filter via a second impedance block;

wherein said first impedance block includes a first impedance element external to the NFC module;

wherein said second impedance block includes a second impedance element external to the NFC module;

said device being adapted to be able to operate in a powered by the field card mode.

14. The device of claim 13,

wherein said first impedance element is further connected in series with a first switch, said first switch being internal to the NFC module;

and

wherein said second impedance element is further connected in series with a second switch, said second switch being internal to the NFC module.

15. The device of claim 13, wherein said antenna circuit is a single-end antenna.

16. The device of claim 15, further comprising a balanced to unbalanced (Balun) transformer coupled between the EMC filter and the antenna circuit.

17. The device of claim 13, wherein said antenna circuit is a differential antenna.

18. The device of claim 13, wherein said device is incorporated in a mobile device and adapted to be powered by the mobile device.

19. The device of claim 13, wherein said device is adapted to perform active load modulation (ALM) in a card mode.

20. The device of claim 13, wherein said device is adapted to perform passive load modulation (PLM) in the powered by the field card mode.