ADAPTIVE IMPEDANCE MATCHING

• US 20130181787A1
• Filed: 03/07/2013
• Published: 07/18/2013
• Est. Priority Date: 04/23/2007
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Blackberry Limited
• Inventors: Manssen, Keith R., Greene, Matthew R., Smith, Wayne E., Blin, Guillaume
• Granted Patent: US 9,698,748 B2
• Time in Patent Office: Days
• US Class Current: 333/17.3
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04
• CPC Class Codes: H03H 2007/386 Multiple band impedance matching
• 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

An embodiment of the present invention provides a method for limiting tuning of a matching network having variable reactive elements coupled to a variable load impedance to at least reduce an undesirable effect caused by an RF signal. Other embodiments are disclosed.

Claims

1. A communication device, comprising:

a matching network including one or more variable reactance elements; and

a controller coupled with the matching network,

wherein the controller adjusts the one or more variable reactance elements to perform tuning responsive to a variable load impedance,

wherein the tuning is an open loop iterative process,

wherein at least a portion of the tuning is performed during a receive mode of the communication device, and

wherein the tuning is limited by at least one of a predetermined number of tuning steps, a predetermined magnitude for each of the tuning steps, a pre-determined time period for the tuning steps or prohibited matching impedance values.

2. The communication device of claim 1, wherein the open loop iterative process is based on a physical use state of the communication device.

3. The communication device of claim 1, further comprising a memory, wherein the tuning is initiated using tuning values for the one or more variable reactance elements that are stored in a look-up table of the memory based on frequency band of operation.

4. The communication device of claim 1, further comprising a transmitter, wherein a portion of the tuning is performed between bursts when the transmitter is inactive.

5. The communication device of claim 1, wherein a portion of the tuning is performed during a transmit mode of the communication device.

6. The communication device of claim 1, wherein the one or more variable reactance elements comprise a variable dielectric capacitor.

7. The communication device of claim 1, wherein the one or more variable reactance elements comprise at least one of a micro-electro-mechanical systems varactor or a semiconductor varactor.

8. The communication device of claim 1, wherein the one or more variable reactance elements comprise a micro-electro-mechanical systems switched reactance component.

9. The communication device of claim 1, wherein the one or more variable reactance elements comprise a semiconductor switched reactance component.

10. A method comprising:

determining tuning steps for a matching network of a communication device to perform tuning responsive to a variable load impedance, wherein the tuning steps are limited by at least one of a predetermined number of tuning steps, a predetermined magnitude for each of the tuning steps, a pre-determined time period for the tuning steps or prohibited matching impedance values; and

adjusting one or more variable reactance elements of the matching network based on the tuning steps for tuning in between bursts when a transmitter of the communication device is inactive.

11. The method of claim 10, wherein the determining of the tuning steps is an open loop iterative process based on a physical use state of the communication device.

12. The method of claim 10, wherein the tuning is initiated using tuning values for the one or more variable reactance elements that are stored in a look-up table of a memory of the communication device based on frequency band of operation.

13. The method of claim 10, wherein the tuning is initiated using tuning values for the one or more variable reactance elements that are stored in a look-up table of a memory of the communication device based on a physical use state of the communication device.

14. A communication device, comprising:

a matching network including one or more variable reactance elements; and

a controller coupled with the matching network,

wherein the controller adjusts the one or more variable reactance elements to perform tuning responsive to a variable load impedance,

wherein the tuning is an open loop iterative process that is initiated using tuning values for the one or more variable reactance elements based on a physical use state of the communication device, and

wherein the tuning is limited by at least one of a predetermined number of tuning steps or a predetermined magnitude for each of the tuning steps.

15. The communication device of claim 14, wherein the tuning is performed during a receive mode of the communication device.

16. The communication device of claim 14, wherein the tuning is performed during a transmit mode of the communication device.

17. The communication device of claim 14, further comprising a transmitter, wherein the tuning is performed between bursts when the transmitter is inactive.

18. The communication device of claim 14, wherein the tuning is limited by prohibited matching impedance values.

19. The communication device of claim 14, wherein the tuning is limited by a pre-determined time period for the tuning steps.

20. The communication device of claim 14, wherein the one or more variable reactance elements comprise a variable dielectric capacitor.