Techniques for improved adaptive impedance matching

• US 20080261544A1
• Filed: 04/23/2007
• Published: 10/23/2008
• Est. Priority Date: 04/23/2007
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Blackberry Limited
• Inventors: Blin, Guillaume
• Granted Patent: US 7,917,104 B2
• Time in Patent Office: Days
• US Class Current: 455/121
• 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 an apparatus, comprising an RF matching network connected to at least one RF input port and at least one RF output port and including one or more voltage or current controlled variable reactive elements; and wherein the RF matching network is tuned to optimize the RF matching network and wherein said tuning is limited by a predetermined number of tuning steps that are taken within a transmit burst and/or limited by the magnitude of each step taken within a transmit burst and/or limited to the steps only being allowed between bursts.

Claims

1. An apparatus, comprising:

an RF matching network connected to at least one RF input port and at least one RF output port and including one or more voltage or current controlled variable reactive elements; and

wherein said RF matching network is tuned to optimize said RF matching network and wherein said tuning is limited by a predetermined number of tuning steps that are taken within a transmit burst and/or limited by the magnitude of each step taken within a transmit burst and/or limited to the steps only being allowed between bursts.

2. The apparatus of claim 1, wherein said tuning steps taken within transmit bursts are accomplished by using time delays corresponding to said transmission bursts.

3. The apparatus of claim 1, wherein said tuning is accomplished by varying the voltage or current to said voltage or current controlled variable reactive elements.

4. The apparatus of claim 3, wherein said variable reactive elements are variable capacitances, variable inductances, or both.

7. The apparatus of claim 1, wherein said variable reactive elements are variable capacitances, variable inductances, or both.

5. An apparatus, comprising:

an RF matching network connected to at least one RF input port and at least one RF output port and including one or more voltage or current controlled variable reactive elements; and

wherein said RF matching network is tuned to optimize said RF matching network and wherein said tuning is limited by a predetermined number of tuning steps that are taken within a transmit burst and/or limited by the magnitude of each step taken within a transmit burst and/or limited to the steps only being allowed between bursts.

6. The apparatus of claim 6, wherein said tuning steps limited to be between transmission bursts is accomplished by allowing tuning only when the transmitter is inactive.

8. An apparatus, comprising:

an RF matching network connected to at least one RF input port and at least one RF output port and including one or more voltage or current controlled variable reactive elements; and

wherein said RF matching network is tuned to optimize said RF matching network and wherein said tuning is limited to avoid certain matching impedances.

9. The apparatus of claim 8, wherein said tuning is adapted to be placed in a “

default”

position when said apparatus is a cellular handset transmitter and at a full power step or any predetermined power step.

10. An apparatus, comprising:

an RF matching network connected to at least one RF input port and at least one RF output port and including one or more voltage or current controlled variable reactive elements;

wherein said RF matching network is tuned to optimize said RF matching network; and

memory to store an optimal impedance match for each frequency band or each group of channels to enable an optimal tuning starting position for a given band or channel.

11. The apparatus of claim 10, wherein said memory is adapted to remember optimal operating positions to better determine the best starting position for said matching network.

12. The apparatus of claim 11, wherein said starting position is used as a starting point for an optimization algorithm.

14. The method of claim 12, further comprising using time delays corresponding to said transmission bursts.

15. The method of claim 12, wherein said tuning is accomplished by varying the voltage or current to said voltage or current controlled variable reactive elements.

13. A method, comprising:

connecting an RF matching network to at least one RF input port and at least one RF output port and including one or more voltage or current controlled variable reactive elements;

tuning said RF matching network to optimize said RF matching network for RF transmissions; and

limiting said tuning by a predetermined number of tuning steps that are taken within a transmit burst and/or limiting the magnitude of each step taken within a transmit burst and/or limiting the steps to only being allowed between bursts.

16. A method, comprising:

connecting an RF matching network to at least one RF input port and at least one RF output port and including one or more voltage or current controlled variable reactive elements;

tuning said RF matching network to optimize said RF matching network for RF transmissions bursts; and

limiting said tuning by a predetermined number of tuning steps that are taken within a transmit burst and/or limiting the magnitude of each step taken within a transmit burst and/or limiting the steps to only being allowed between bursts.

17. The method of claim 16, further comprising allowing tuning only when the transmitter is inactive.

18. The apparatus of claim 16, wherein said variable reactive elements are variable capacitances, variable inductances, or both.

19. A method, comprising:

connecting an RF matching network to at least one RF input port and at least one RF output port and including one or more voltage or current controlled variable reactive elements;

tuning said RF matching network to optimize said RF matching network; and

limiting said tuning to avoid certain matching impedances at predetermined parameters.

20. The method of claim 19, further comprising adapting said tuning to be placed in a “

default”

position when said apparatus is a cellular handset transmitter and at a full power step.

21. A method, comprising:

connecting an RF matching network to at least one RF input port and at least one RF output port and including one or more voltage or current controlled variable reactive elements;

tuning said RF matching network to optimize said RF matching network; and

storing in memory an optimal impedance match for each frequency band or each group of channels to enable an optimal tuning starting position for a given band or channel.

22. The method of claim 21, further comprising adapting said memory to remember operating positions to better determine the best starting position for said matching network.

23. The method of claim 21, wherein said operating positions are flip-open or flip-closed.