Method and system for optimizing transmit power of a power amplifier using a battery voltage (Vbat) monitor

• US 8,224,270 B2
• Filed: 12/29/2006
• Issued: 07/17/2012
• Est. Priority Date: 12/06/2006
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Behzad, Arya
• Primary Examiner(s): PHU, SANH D
• Application Number:
  US11/618,195
• Publication Number:
  US 20080139146A1
• Time in Patent Office: 2,027 Days
• Field of Search: 455/127.2, 455/247.1, 455/234.1, 455/234.2, 455/232.1, 455/250.1, 375/345, 375/142
• US Class Current: 455/127.2
• CPC Class Codes: H03G 3/007 Control dependent on the supply voltage
• 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: Y02D 30/70 in wireless communication networks

Abstract

Methods, systems, and machine-readable code for optimizing transmit power of a power amplifier using a V_bat monitor are disclosed and may comprise adjusting the gain of gain stages in a transmit path based on a control signal that is a function of a supply voltage signal, among other variables, derived from a supply voltage that may be used to power a transmit path. The supply voltage signal may be received from a power management unit or derived directly from a battery or other supply. The supply voltage signal may be compared to a reference signal, the result of which may be utilized to generate the control signal. The values for the control signals may be determined over a range of supply voltages and stored in a lookup table.

Claims

1. A method for controlling a circuit within a transmitter, the method comprising:

adjusting a gain of at least one of a plurality of gain stages in an RF transmit path based on a control signal that is indicative of a measured battery voltage, wherein said gain is adjusted based on a voltage range that enables configuration of each of said at least one of said plurality of gain stages to meet performance requirements,

wherein adjusting the gain comprises increasing the gain of at least one of the plurality of gain stages responsive to the measured battery voltage being higher than a designed voltage corresponding to the plurality of gain stages.

2. The method according to claim 1, comprising receiving a battery voltage signal measured from a battery used to power a transmit path.

3. The method according to claim 2, wherein said battery voltage signal is generated by a power management unit.

4. The method according to claim 2, wherein said battery voltage signal is measured directly from said battery.

5. The method according to claim 2, wherein said control signal is generated based on said measured battery voltage signal.

6. The method according to claim 1, comprising comparing said battery voltage to a reference voltage, wherein the reference voltage is independent of temperature.

7. The method according to claim 6, comprising generating said control signal based on said comparison.

8. The method according to claim 1, wherein a plurality of values for said control signal for a corresponding plurality of said battery voltage values are stored in a lookup table, wherein the plurality of values for said control signal are calibrated to meet performance requirements.

9. The method according to claim 8, comprising determining said control signal that is indicative of said battery voltage from said lookup table.

10. The method according to claim 1, wherein said gain is adjusted to meet performance metrics comprising one or more of transmit power, voltage standing wave ratio, and modulation type.

11. A system for controlling a circuit within a transmitter, the system comprising:

one or more circuits in a chip configured to adjust a gain of at least one of a plurality of gain stages in an RF transmit path based on a control signal that is indicative of a measured battery voltage, wherein said gain is adjusted based on a voltage range that enables configuration of each of said at least one of said plurality of gain stages to meet performance requirements, wherein gain levels associated with values of the control signal are calibrated over a range of battery voltages, and wherein the values are stored in a lookup table.

12. The system according to claim 11, wherein said one or more circuits receives a battery voltage signal measured from a battery used to power a transmit path, and wherein the one or more circuits configured to adjust the gain is further configured to increase the gain of at least one of the plurality of gain stages responsive to a battery corresponding to the measured battery voltage being recently charged.

13. The system according to claim 12, wherein said one or more circuits receives said battery voltage signal generated by a power management unit.

14. The system according to claim 12, wherein said one or more circuits measures said battery voltage signal directly from said supply.

15. The system according to claim 12, wherein said one or more circuits generates said control signal based on said measured battery voltage signal.

16. The system according to claim 11, wherein said one or more circuits compares said battery voltage to a reference voltage.

17. The system according to claim 16, wherein said one or more circuits generates said control signal based on said comparison.

18. The system according to claim 11, wherein said one or more circuits determines said control signal that is indicative of said battery voltage from said lookup table.

19. The system according to claim 11, wherein said one or more circuits adjusts said gain based on one or more of transmit power, voltage standing wave ratio, and modulation type.

20. A machine-readable storage having stored thereon, a computer program having at least one code section for controlling a circuit in a transmitter, the at least one code section being executable by a machine for causing the machine to perform steps comprising:

adjusting a gain of at least one of a plurality of gain stages in an RF transmit path based on a control signal that is indicative of a measured battery voltage, wherein said gain is adjusted based on a voltage range that enables configuration of each of said at least one of said plurality of gain stages to meet performance requirements, wherein adjusting the gain comprises increasing the gain of at least one of the plurality of gain stages responsive to the measured battery voltage being higher than a designed voltage corresponding to the plurality of gain stages, wherein gain levels associated with values of the control signal are calibrated over a battery voltage range based on performance requirements.

21. The machine readable storage according to claim 20, wherein said at least one code section comprises code for receiving a battery voltage signal measured from a battery used to power a transmit path.

22. The machine readable storage according to claim 21, wherein said at least one code section comprises code for receiving said battery voltage signal generated by a power management unit.

23. The machine readable storage according to claim 21, wherein said at least one code section comprises code for measuring said battery voltage signal directly from said battery.

24. The machine readable storage according to claim 21, wherein said at least one code section comprises code for generating said control signal based on said measured battery voltage signal.

25. The machine readable storage according to claim 20, wherein said at least one code section comprises code for comparing said battery voltage to a reference voltage.

26. The machine readable storage according to claim 25, wherein said at least one code section comprises code for generating said control signal based on said comparison.

27. The machine readable storage according to claim 20, wherein said at least one code section comprises code for storing a plurality of values for said control signal for a corresponding plurality of said battery voltage values in a lookup table.

28. The machine readable storage according to claim 27, wherein said at least one code section comprises code for determining said control signal that is indicative of said battery voltage from said lookup table.

29. The machine readable storage according to claim 20, wherein said at least one code section comprises code for adjusting said gain based on one or more of transmit power, voltage standing wave ratio, and modulation type.