Methods for tuning an adaptive impedance matching network with a look-up table

• US 8,674,783 B2
• Filed: 03/12/2013
• Issued: 03/18/2014
• Est. Priority Date: 09/24/2008
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Blackberry Limited
• Inventors: Spears, John Hanford, Smith, Wayne Eric, Zhu, Yongfei, Sui, Chenggang
• Primary Examiner(s): JONES, STEPHEN E
• Application Number:
  US13/795,930
• Publication Number:
  US 20130187727A1
• Time in Patent Office: 371 Days
• Field of Search: 333/32, 333/17.3
• US Class Current: 333/17.3
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• CPC Class Codes: H03H 11/30 Automatic matching of source impedance to load impedance
• CPC Class Codes: H03H 7/40 Automatic matching of load impedance to source impedance
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H

Abstract

Methods for generating a look-up table relating a plurality of complex reflection coefficients to a plurality of matched states for a tunable matching network. Typical steps include measuring a plurality of complex reflection coefficients resulting from a plurality of impedance loads while the tunable matching network is in a predetermined state, determining a plurality of matched states for the plurality of impedance loads, with a matched state determined for each of the plurality of impedance loads and providing the determined matched states as a look-up table. A further step is interpolating the measured complex reflection coefficients and the determined matching states into a set of complex reflection coefficients with predetermined step sizes.

Claims

1. A method comprising:

determining, by a controller of a communication device, a parameter associated with a communication device, wherein the parameter is selected from a group of parameters consisting essentially of complex reflection coefficient, current drain, incident power, reflected power, temperature, input power level, reliability metrics, and linearity metrics;

identifying, by the controller, a tuning step based on determining a closest match to the parameter in a lookup table stored in the communication device, wherein the lookup table contains sets of parameters corresponding to matched states for a tunable impedance matching network of the communication device;

dividing the tuning step into a group of tuning steps; and

tuning the tunable impedance matching network utilizing the group of tuning steps.

2. The method of claim 1, wherein the tuning step is an initial tuning step for a communication session.

3. The method of claim 1, wherein the determining of the parameter comprises making measurements via a power detector coupled between a power amplifier and an antenna of the communication device.

4. The method of claim 1, wherein the tuning of the tunable impedance matching network comprises adjusting one or more voltage tunable ferroelectric capacitors of the tunable impedance matching network.

5. The method of claim 1, wherein the tuning of the tunable impedance matching network comprises adjusting one or more MEMS variable reactance elements of the tunable impedance matching network.

6. The method of claim 1, wherein the tuning of the tunable impedance matching network comprises adjusting one or more tunable inductors of the tunable impedance matching network.

7. The method of claim 1, wherein the group of tuning steps comprises digital-to-analog settings.

8. The method of claim 1, wherein the identifying of the tuning step based on the determining of the closest match to the parameter in the lookup table is according to identified band information for operation of the communication device.

9. The method of claim 1, wherein the dividing of the tuning step into the group of tuning steps is based on a maximum allowable tuning step according to an operational specification.

10. The method of claim 9, wherein the operational specification comprises a modulation accuracy specification.

11. The method of claim 9, wherein the operational specification comprises a time mask specification.

12. A method comprising:

determining, by a controller of a communication device, a parameter associated with a communication device;

identifying, by the controller, a tuning step based on determining a closest match to the parameter in a lookup table, wherein the lookup table contains sets of parameters corresponding to matched states for a tunable impedance matching network of the communication device;

dividing the tuning step into a group of tuning steps, wherein the dividing of the tuning step into the group of tuning steps is based on a maximum allowable tuning step according to an operational specification; and

tuning the tunable impedance matching network utilizing the group of tuning steps.

13. The method of claim 12, wherein the parameter comprises complex reflection coefficients.

14. The method of claim 12, wherein the parameter comprises current drain.

15. The method of claim 12, wherein the parameter comprises incident power.

16. The method of claim 12, wherein the parameter comprises reflected power.

17. The method of claim 12, wherein the parameter comprises input power level.

18. The method of claim 12, wherein the parameter comprises linearity metrics.