Method and system for utilizing a frequency modulation (FM) antenna system for near field communication (NFC) and radio frequency identification (RFID)

• US 8,311,504 B2
• Filed: 03/14/2011
• Issued: 11/13/2012
• Est. Priority Date: 09/29/2006
• Status: Expired due to Fees

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Rofougaran, Ahmadreza
• Primary Examiner(s): Jackson, Blane J
• Application Number:
  US13/047,222
• Publication Number:
  US 20110165838A1
• Time in Patent Office: 610 Days
• Field of Search: 455/41.1, 455/41.2, 455/41.3, 455/42, 455/66.1, 455/90.1, 455/90.3, 455/107, 455/121, 455/129, 455/575.1, 455/575.7, 455/122, 455/123, 455/562.1, 455/269, 455/270, 455/272, 455/273, 455/274, 455/275, 455/276.1, 455/277.1, 455/280, 455/290
• US Class Current: 455/277.1
• CPC Class Codes: H04B 5/48 Transceivers

Abstract

A method for wireless communication is provided and may include configuring at least one capacitor array in an antenna system to control a frequency for receiving external signals. An antenna and at least one inductor in the antenna system may be configured for receiving external signals at a first frequency. An inductor and a voltage source, a capacitor, and/or a ground reference may be configured for receiving the external signals at a different frequency if the frequency is utilized for backscattered signal reception and/or magnetically coupled signal reception. Near field communication (NFC) signals may be received at the different frequency for backscattered signals. Radio frequency identification (RFID) signals may be received at the different frequency for magnetically coupled signals. The first frequency may be within the FM frequency band. The antenna system may be configured to transmit signals to be subsequently received as backscattered signals or magnetically coupled signals.

Claims

1. A system for wireless communication, said system comprising:

a radio frequency (RF) transceiver coupled to one or more inductors, said RF transceiver configured to receive a wireless signal;

a control circuit configured to utilize a switch to couple an antenna to said one or more inductors when a frequency of said wireless signal is utilized for frequency modulation (FM) signal reception;

wherein said control circuit is configured to utilize said switch to couple a bias voltage to said one or more inductors when said frequency of said wireless signal is utilized for near field communications (NFC) or radio frequency identification (RFID) communications signal reception.

2. The system of claim 1, wherein said control circuit is configured to select said frequency of said wireless signal by adjusting a capacitance of one or more capacitive arrays coupled to said one or more inductors.

3. The system of claim 2, wherein each of said one or more capacitive arrays comprises a plurality of switches configured to couple one or more of a plurality of capacitors to each of said one or more capacitive arrays.

4. The system of claim 1, wherein said bias voltage comprises one of a voltage source, a capacitor and a ground reference.

5. The system of claim 1, wherein said frequency of said wireless signal utilized for said FM signal reception is between 87.5 MHz and 108 MHz.

6. The system of claim 1, wherein said frequency of said wireless signal utilized for said NFC or RFID communications is approximately 13.5 MHz.

7. The system of claim 1, wherein said control circuit is configured to compensate for a center frequency drift of said wireless signal by adjusting a capacitance of one or more capacitive arrays coupled to said one or more inductors.

8. The system of claim 2, wherein said control circuit is configured to select a modified version of said frequency to receive an FM signal at said modified version of said frequency.

9. The system of claim 1, wherein said RF transceiver enables detection of electromagnetic energy in a wireless medium for said NFC or RFID communications signal reception via said one or more inductors.

10. The system of claim 9, wherein said RF transceiver receives data in said wireless signal based on detected variations in a strength of said electromagnetic energy.

11. A method for wireless communication, said method comprising:

in a system comprising a radio frequency (RF) transceiver coupled to one or more inductors;

selecting a frequency of a wireless signal by adjusting a capacitance of one or more capacitive arrays coupled to said one or more inductors;

configuring a switch to couple an antenna to said one or more inductors when a frequency of said wireless signal is utilized for frequency modulation (FM) signal reception;

configuring said switch to couple a bias voltage to said one or more inductors when said frequency of said wireless signal is utilized for near field communications (NFC) or radio frequency identification (RFID) communications signal reception.

12. The method of claim 11, wherein said adjusting said capacitance of said one or more capacitive arrays further comprises utilizing a plurality of switches to couple one or more of a plurality of capacitors to each of said one or more capacitive arrays.

13. The method of claim 11, wherein said bias voltage comprises one of a voltage source, a capacitor and a ground reference.

14. The method of claim 11, wherein said frequency of said wireless signal utilized for said FM signal reception is between 87.5 MHz and 108 MHz.

15. The method of claim 11, wherein said frequency of said wireless signal utilized for said NFC or RFID communications is approximately 13.5 MHz.

16. The method of claim 11, further comprising compensating for a center frequency drift of said wireless signal by adjusting said capacitance of said one or more capacitive arrays coupled to said one or more inductors.

17. The method of claim 11, further comprising determining a center frequency drift of said wireless signal utilizing a received signal strength indication of said wireless signal or a bit error rate of said wireless signal.

18. The method of claim 11, further comprising selecting a modified version of said frequency to receive an FM signal at said modified version of said frequency.

19. The method of claim 11, further comprising detecting electromagnetic energy in a wireless medium for said NFC or RFID communications signal reception via said one or more inductors.

20. The method of claim 19, wherein said RF transceiver receives data in said wireless signal based on detected variations in a strength of said electromagnetic energy.