TUNING MATCHING CIRCUITS FOR TRANSMITTER AND RECEIVER BANDS AS A FUNCTION OF TRANSMITTER METRICS

• US 20090121963A1
• Filed: 11/14/2007
• Published: 05/14/2009
• Est. Priority Date: 11/14/2007
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Paratek Microwave Incorporated (Blackberry Limited)
• Inventors: Greene, Matthew R.
• Granted Patent: US 7,991,363 B2
• Time in Patent Office: Days
• US Class Current: 343/861
• 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
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition

Abstract

A tunable matching circuit is adjusted primarily based on transmitter oriented metrics and is then applied to attain a desired tuning for transmitter and receiver operation. In a TDM system, this is accomplished by identifying an optimal tuning for the transmitter and then applying an empirically derived adjustment to the tuning circuit in receiver mode. In an FDM system, this is accomplished by identifying a target operation that is a compromise between transmitter performance and receiver performance, and then adjusting the tuning circuit as a function of transmitter metrics and the current tuning values to achieve the desired compromised performance.

Claims

1. A method for controlling a matching circuit for interfacing an antenna with a transceiver, the matching circuit including at least one variable component, the method comprising the steps of:

obtaining at least one operational metric for a transmitter;

calculating a current figure of merit as a function of the at least one operational metric;

comparing the current figure of merit to a target figure of merit; and

adjusting a setting of the at least one variable component to a value expected to change the current figure of merit relative to the target figure of merit, whereby the receiver operation and transmitter operation are adjusted based on transmitter operational metrics.

2. The method of claim 1, further comprising the step of repeating the process to adjust the matching circuit by obtaining a next at least one operational metric for the transmitter.

3. The method of claim 2, wherein the matching circuit operates in a time division multiplexed system and wherein the step of adjusting the setting is performed during a transmit time slot, and further comprising the step of modifying the setting as a function of the adjustment value for use during a receive time slot to improve the performance of the receiver.

4. The method of claim 3, wherein the operational metric comprises transmitter reflection loss.

5. The method of claim 3, wherein the operational metric comprises output power of the transmitter.

6. The method of claim 3, wherein the operational metric comprises current drain.

7. The method of claim 3, wherein the operational metric comprises transmitter linearity.

8. The method of claim 3, wherein the step of modifying the setting as a function of the adjustment value further comprises determining a change in the value that is proximate to tuning the matching circuit to a point that minimizes the receiver reflection loss.

9. The method of claim 8, wherein the step of determining a change in the value further comprises determining a change in the value as a function of one or more modes of operation.

10. The method of claim 8, wherein the step of determining a change in the value further comprises detecting a current mode of operation and selecting a change in the value based on the detected mode of operation.

11. The method of claim 2, wherein the matching circuit operates in a frequency division multiplexed system in which the transmit frequency is different than the receive frequency and the current figure of merit is a function of one or more transmitter metrics and preferences for the value of the one or more variable components.

12. The method of claim 11, wherein the step of adjusting the setting of the at least one variable component attains a compromise between transmitter and receiver performance by approaching a target figure of merit existing at an operational point at which the transmitter reflection loss and the receiver reflection loss are most closely proximate to a respective target reflection loss for the transmitter and the receiver.

13. The method of claim 11, wherein the operational metric comprises the transmitter reflection loss.

14. The method of claim 11, wherein the operational metric comprises the output power of the transmitter.

15. The method of claim 11, wherein the operational metric comprises the current drain.

16. The method of claim 11, wherein the operational metric comprises the transmitter linearity.

17. The method of claim 1, wherein the matching circuit operates in a frequency division multiplexed system in which the transmit frequency is different than the receive frequency and the current figure of merit is a function of a magnitude and a phase of a transmitter reflection loss, and the step of adjusting the setting of the at least one variable component to a value expected to change the current figure of merit relative to the target figure of merit further comprises adjusting to optimize the current figure of merit by meeting a target magnitude and the target phase of the transmitter reflection loss.

18. The method of claim 1, wherein the step of adjusting the setting of the at least one variable component to a value expected to change the current figure of merit relative to the target figure of merit further comprises adjusting the setting to a value as a function of historical results of previous adjustments.

19. The method of claim 1, wherein the matching circuit operates in a frequency division multiplexed system in which the transmitter frequency is different than the receiver frequency and the current figure of merit is a function of target transmitter metrics and preferences for the value of the one or more variable components, and the step of adjusting the setting of the at least one variable component to a value expected to change the current figure of merit relative to the target figure of merit further comprises detecting a mode of operation and adjusting the settings to a value as a function of the detected mode of operation.

20. The method of claim 1, further comprising the step of storing the value for future use.

21. The method of claim 1, further comprising the step of storing the value and associating the value with a mode of operation.

22. The method of claim 21, further comprising the step of initially extracting a previously stored value associated with a current mode of operation and adjusting the setting of the one or more variable components to the extracted value prior to the step of detecting at least one operational metric for the transmitter.

23. The method of claim 1, wherein the matching circuit operates in a frequency division multiplexed system and the step of adjusting a setting of the at least one variable component to a value expected to change the current figure of merit relative to the target figure of merit further comprises the steps of:

adjusting the setting to a value that optimizes the transmitter operation;

modifying the setting as a function of the value that optimizes transmitter operation to attain a desired level of operation for both the transmitter and receiver.

24. An apparatus, comprising:

a matching network connected to at least one input port and at least one output port and including one or more variable components; and

wherein said matching network is tuned to optimize said matching network based on transmitter oriented metrics which are then applied to achieve desired transmitter and receiver operation.

25. The apparatus of claim 24, wherein the apparatus operates in a TDM system and the application of the transmitter oriented metrics comprises tuning the matching network relative to optimal transmitter operation based on empirically characterized receiver operation.

26. The apparatus of claim 24, wherein the apparatus operates in an FDM system and the application of the transmitter oriented metrics comprises identifying a tuning state that compromises transmitter operation with receiver operation.

27. A communication device including a transceiver that is interfaced to an antenna through a tunable circuit, the communication device comprising:

a matching network connected between the transceiver and including one or more variable components; and

wherein said matching network is tuned to optimize said matching network based on transmitter oriented metrics which are then applied to achieve desired transmitter and receiver operation.