STATIC TUNING OF WIRELESS TRANSMITTERS

• US 20140080409A1
• Filed: 09/17/2012
• Published: 03/20/2014
• Est. Priority Date: 09/17/2012
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Frankland, Stephen, Legge, Terence
• Application Number:
  US13/621,762
• Publication Number:
  US 20140080409A1
• Time in Patent Office: Days
• US Class Current: 455/41.1
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/50 using additional energy repeaters between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H04B 17/104 of other parameters, e.g. DC offset, delay or propagation times
• CPC Class Codes: H04B 17/11 for calibration
• CPC Class Codes: H04B 5/0037 for power transfer
• CPC Class Codes: H04B 5/0075 using inductive coupling transformers or inductances adapted for inductive coupling H01F38/14
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A method and device for static tuning of wireless transmitters is disclosed. In some aspects, the antenna circuit can be located on a circuit board and configured to generate a wireless field and resonate at a resonant frequency. A tuning signal is applied an antenna circuit to drive the antenna circuit. A signal of the resonant frequency of the antenna circuit is detected and an adjustment value is determined based on the detected signal. A reactance of a variable reactance component is adjusted based on the adjustment value to maintain the resonant frequency in a range between a first frequency that is less than the detected resonant frequency and a second frequency that is greater than the detected resonant frequency.

Claims

1. An apparatus for operating a wireless device comprising:

a controller configured to apply a tuning signal to an antenna circuit to drive the antenna circuit, the antenna circuit being located on a circuit board and configured to generate a wireless field and resonate at a resonant frequency;

a detector configured to detect a signal indicative of the resonant frequency of the driven antenna circuit; and

a variable reactance component coupled to the antenna circuit, wherein the controller is configured to determine an adjustment value based on the detected signal, and wherein the controller is configured to adjust a reactance of the variable reactance component based on the adjustment value to maintain a resonant frequency in a range between a first frequency that is less than the detected resonant frequency and a second frequency that is greater than the detected resonant frequency.

2. The apparatus of claim 1, wherein the first frequency and the second frequency are centered about the detected resonant frequency.

3. The apparatus of claim 1, wherein the wireless field includes near-field communication (NFC) signals, and wherein the circuit board comprises a printed circuit board (PCB).

4. The apparatus of claim 1, wherein the antenna circuit includes a coil.

5. The apparatus of claim 1, wherein the controller is configured to apply a tuning signal during an initial device configuration routine following integration of the circuit in a portable electronic device.

6. The apparatus of claim 1, further comprising a memory configured to store initial calibration settings, and wherein the controller is configured to adjust the variable reactance component based on the initial calibration settings.

7. The apparatus of claim 1, wherein the antenna circuit includes a coil, and wherein the variable reactance component comprises a variable capacitor coupled in parallel with the coil.

8. A method for operating a wireless device comprising:

applying a tuning signal to an antenna circuit to drive the antenna circuit, the antenna circuit being located on a circuit board and configured to generate a wireless field and resonate at a resonant frequency;

detecting a signal of the resonant frequency of the antenna circuit;

determining an adjustment value based on the detected signal; and

adjusting the reactance of a variable reactance component based on the adjustment value to maintain a resonant frequency in a range between a first frequency that is less than the detected resonant frequency and a second frequency that is greater than the detected resonant frequency.

9. The method of claim 8, wherein the first frequency and the second frequency are centered about the detected resonant frequency.

10. The method of claim 8, wherein the wireless field includes near-field communication (NFC) signals, and wherein the circuit board comprises a printed circuit board (PCB).

11. The method of claim 8, wherein the antenna circuit includes a coil.

12. The method of claim 8, wherein a tuning signal is applied to the antenna circuit to drive the antenna circuit during an initial device configuration routine following integration of the circuit in a portable electronic device.

13. The method of claim 8, further comprising a memory configured to store initial calibration settings, and wherein the controller is configured to adjust the variable reactance component based on the initial calibration settings.

14. The method of claim 8, wherein the antenna circuit includes a coil, and wherein the variable reactance component comprises a variable capacitor coupled in parallel with the coil.

15. A method comprising:

receiving an adjustment value;

adjusting the reactance of a variable reactance component based on the adjustment value to maintain a resonant frequency in a range between a first frequency that is less than the detected resonant frequency and a second frequency that is greater than the detected resonant frequency.

16. The method of claim 15, wherein the first frequency and the second frequency are centered about the detected resonant frequency.

17. The method of claim 15, further comprising a memory configured to store initial calibration settings, and wherein the variable reactance component is adjusted based on the initial calibration settings.

18. The method of claim 17, wherein the memory is located on a circuit board.

19. An apparatus for operating a wireless device comprising:

means for applying a tuning signal to an antenna circuit to drive the antenna circuit, the antenna circuit being located on a circuit board and configured to generate a wireless field and resonate at a resonant frequency;

means for detecting a signal indicative of the resonant frequency of the antenna circuit;

means for determining an adjustment value based on the detected signal; and

means for adjusting the reactance of a reactance component based on the adjustment value to maintain a resonant frequency in a range between a first frequency that is less than the detected resonant frequency and a second frequency that is greater than the detected resonant frequency.

20. The apparatus of claim 19, wherein the first frequency and the second frequency are centered about the detected frequency.

21. The apparatus of claim 19, wherein the wireless field includes near-field communication (NFC) signals, and wherein the circuit board comprises a printed circuit board (PCB).

22. The apparatus of claim 19, wherein the antenna circuit includes a coil.

23. The apparatus of claim 19, wherein the controller is configured to apply a tuning signal during an initial device configuration routine following integration of the circuit in a portable electronic device.

24. The apparatus of claim 19, further comprising a memory configured to store initial calibration settings, and wherein the controller is configured to adjust the variable reactance component based on the initial calibration settings.

25. The apparatus of claim 19, wherein the antenna circuit includes a coil, and wherein the variable reactance component comprises a variable capacitor coupled in parallel with the coil.

26. An apparatus comprising:

a controller received an adjustment value from a memory; and

a variable reactance component coupled to an antenna circuit, wherein the controller is configured to adjust the reactance of the variable reactance component based on the adjustment value to maintain a resonant frequency in a range between a first frequency that is less than the detected resonant frequency and a second frequency that is greater than the detected resonant frequency.

27. The apparatus of claim 26, wherein the first frequency and the second frequency are centered about the detected resonant frequency.

28. The apparatus of claim 26, wherein the memory is configured to store initial calibration settings, and wherein the variable reactance components is adjusted based on the initial calibration settings.

29. The apparatus of claim 26, wherein a memory is located on a circuit board and stores calibration setting.

30. The apparatus of claim 26, wherein the antenna circuit includes a coil.

31. The apparatus of claim 26, wherein the controller is configured to apply a tuning signal during an initial device configuration routine following integration of the circuit in a portable electronic device.

32. The apparatus of claim 26, wherein the antenna circuit includes a coil, and wherein the variable reactance component comprises a variable capacitor coupled in parallel with the coil.

33. An apparatus comprising:

means for requesting an adjustment value from a memory;

means for adjusting the reactance of a variable reactance component based on the adjustment value to maintain a resonant frequency in a range between a first frequency that is less than the detected resonant frequency and a second frequency that is greater than the detected resonant frequency.

34. The apparatus of claim 33, wherein the memory is located on a circuit board and stores calibration setting.

35. The apparatus of claim 33, wherein the first frequency and the second frequency are centered about the detected resonant frequency.

36. The apparatus of claim 33, wherein the memory is configured to store initial calibration settings, and wherein the variable reactance component is adjusted based on the initial calibration settings.