NFC device and method of operating the same

Patent metadata

Field	Value
Publication number	US-11005534-B2
Application number	US-202016988852-A
Country	US
Kind code	B2
Filing date	Aug 10, 2020
Priority date	Sep 9, 2019
Publication date	May 11, 2021
Grant date	May 11, 2021

Abstract

In accordance with a first aspect of the present disclosure, a near field communication (NFC) device is provided, comprising: a modulator configured to modulate a carrier signal received from an external reader, resulting in a modulated carrier signal; a controller configured to control a transmission of the modulated carrier signal to the external reader; a transmitter driver configured to transmit said modulated carrier signal, said transmitter driver having a variable resistance; wherein the controller is further configured to change said variable resistance during a modulation phase of the NFC device such that a clock synchronization window is widened. In accordance with a second aspect of the present disclosure, a corresponding method of operating an NFC device is conceived. In accordance with a third aspect of the present disclosure, a non-transitory machine-readable medium is provided, comprising instructions which, when executed, carry out a method of the kind set forth.

First claim

The invention claimed is:

1. A near field communication, NFC, device, comprising:
a modulator configured to modulate a carrier signal received from an external reader, resulting in a modulated carrier signal;
a controller configured to control a transmission of the modulated carrier signal to the external reader; and
a transmitter driver configured to transmit said modulated carrier signal, said transmitter driver having a variable resistance;
wherein the controller is further configured to change said variable resistance during a modulation phase of the NFC device such that a clock synchronization window is widened;
wherein the controller is configured to change said variable resistance by selecting a resistance from a plurality of different resistances; and
wherein the controller is configured to select different resistances for consecutive transmission pulses during the modulation phase.

2. The NFC device of claim 1 , wherein the controller is further configured to select different resistances during the non-modulation phase.

3. The NFC device of claim 1 , wherein the controller is further configured to remove one or more transmission pulses at a beginning of one or more modulation phases of the NFC device.

4. The NFC device of claim 1 , further comprising a receiver for receiving the carrier signal, wherein the controller is further configured to control a reception of the carrier signal and to change, during the modulation phase of the NFC device, a variable resistance of an HF attenuator comprised in said receiver.

5. The NFC device of claim 4 , wherein the controller is configured to change said variable resistance of the HF attenuator by selecting a resistance from a plurality of different resistances.

6. The NFC device of claim 5 , wherein the controller is configured to select different resistances for consecutive transmission pulses during the modulation phase.

7. The NFC device of claim 6 , wherein the controller is further configured to select different resistances during the non-modulation phase.

8. A mobile device comprising the NFC device of claim 1 .

9. A method of operating a near field communication, NFC, device, the method comprising:
modulating, by a modulator, a carrier signal received from an external reader, resulting in a modulated carrier signal;
controlling, using a controller, a transmission of the modulated carrier signal to the external reader; and
transmitting, by a transmitter driver, said modulated carrier signal, said transmitter driver having a variable resistance;
wherein the controller changes said variable resistance during a modulation phase of the NFC device such that a clock synchronization window is widened;
wherein the controller changes said variable resistance by selecting a resistance from a plurality of different resistances; and
wherein the controller changes said variable resistance by selecting a resistance from a plurality of different resistances.

10. The method of claim 9 , wherein the controller selects different resistances during the non-modulation phase.

11. The method of claim 9 , wherein the controller removes one or more transmission pulses at a beginning of one or more modulation phases of the NFC device.

12. The method of claim 9 , wherein the controller further controls a reception of the carrier signal by a receiver and changes, during the modulation phase of the NFC device, a variable resistance of an HF attenuator comprised in said receiver.

13. The method of claim 12 , wherein the controller changes said variable resistance of the HF attenuator by selecting a resistance from a plurality of different resistances.

14. The method of claim 13 , wherein the controller selects different resistances for consecutive transmission pulses during the modulation phase.

15. The method of claim 14 , wherein the controller selects different resistances during the non-modulation phase.

16. The method of claim 9 , wherein the method is implemented as instructions stored on a non-transitory machine-readable medium.

Assignees

• Nxp Bv

Inventors

• Nunziata Fred George
• Buchsbaum Martin
• Merlin Erich
• Krenn Adrian Rafael

Classifications

• G06K19/0723

  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 title

• G06K7/10148

  the step consisting of dynamically tuning the resonant circuit of the interrogation device that is emitting the interrogation signal, e.g. for impedance matching inside of the interrogation device (for tuning related to loop aerials in general H01Q7/00) · CPC title

• H04B5/0056 Primary

  Electricity · mapped topic

• H04B5/72 Primary

  for local intradevice communication · CPC title

• H04B5/77 Primary

  for interrogation · CPC title