NEAR FIELD COMMUNICATION (NFC) ACTIVATION

• US 20100045441A1
• Filed: 11/15/2007
• Published: 02/25/2010
• Est. Priority Date: 11/15/2006
• Status: Abandoned Application

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Del Prado, Javier, Hirsch, Olaf, Everaere, Dominique
• Application Number:
  US12/514,641
• Publication Number:
  US 20100045441A1
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: H04B 5/22 Capacitive coupling
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

The present invention discloses a method and a system for activating a communication device in presence of a field generated by a near field communication (NFC) tag reader in a near field communication (NFC) environment. The presence of a field generated by a NFC tag reader is automatically detected using detection circuits. Once the field is detected, the presence of the field is signaled to the communication devices associated with the NFC environment. The communication devices are then switched automatically to an appropriate mode according to the field. The method and system of the present invention removes the additional user interaction in pairing various communication devices in the NFC environment.

Claims

1. A method for activating a communication device in presence of a field generated by a near field communication tag reader in a near field communication environment comprising the steps of:

detecting said presence of the field generated by said near field communication tag reader automatically;

signaling the presence of the field to said communication device if the field is detected; and

switching the communication device automatically to an appropriate mode according to the field detected in the detecting step.

2. The method of claim 1, wherein said detecting the presence of the field comprises:

building a resonant circuit for generating an alternate voltage in the presence of the field generated by the; and

rectifying and averaging said alternate voltage.

3. The method of claim 2, wherein said resonant circuit comprises an inductor and a variable capacitor coupled in parallel.

4. The method of claim 2, wherein the alternate voltage is rectified using a diode and averaged using a capacitor.

5. The method of claim 2 further comprises limiting the output voltage for protecting a receiving circuit using a Zener diode.

6. The method of claim 2 further comprises setting the frequency of the resonant circuit equal to the frequency of said magnetic field using said variable capacitor.

7. The method of claim 1, wherein the steps of detecting, signaling and switching are performed without user interaction, whereby the user interaction for activating the communication device is eliminated.

8. The method of claim 1, wherein said communication device comprises a Bluetooth device.

9. A system for detecting the presence of a field generated by a near field communication tag reader in a near field communication environment comprising:

a resonant circuit for generating an alternate voltage in the presence of said field generated by said near field communication tag reader; and

a diode for rectifying and a capacitor for averaging said alternate voltage respectively.

10. The system of claim 9 further comprises:

a Zener diode for limiting the output voltage of the system to a receiving circuit.

11. The system of claim 9, wherein said resonant circuit comprises:

an inductor and a variable capacitor coupled in parallel, the value of said variable capacitor is set such that the resonant circuit has the same frequency as the field generated by said near field communication tag reader.