IMPROVED CONTROL OF SWITCHER REGULATED POWER AMPLIFIER MODULES

• US 20120122411A1
• Filed: 01/17/2012
• Published: 05/17/2012
• Est. Priority Date: 06/14/2006
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Chan, Wen-Yen, Khan, Nasserullah
• Granted Patent: US 8,295,792 B2
• Time in Patent Office: Days
• US Class Current: 455/126
• CPC Class Codes: H03F 1/02 Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
• CPC Class Codes: H03F 1/0227 using supply converters
• CPC Class Codes: H03F 1/34 Negative-feedback-circuit arrangements with or without positive feedback H03F1/02 - H03F1/30, H03F1/38 - H03F1/50, H03F3/50 take precedence ; for rejection of common mode signals H03F3/45479
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03G 3/004 Control by varying 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: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 2001/0433 with linearisation using feedback
• CPC Class Codes: H04B 2001/045 with means for improving efficiency

Abstract

Various embodiments described herein relate to a power management block and an amplification block used in the transmitter of a communication subsystem. The power management block provides improved control for the gain control signal provided to a pre-amplifier and the supply voltage provided to a power amplifier which are both in the amplification block. The power expended by the power amplifier is optimized by employing a continuous control method in which one or more feedback loops are employed to take into account various characteristics of the transmitter components and control values.

Claims

1. A control system for a transmitter of a wireless device, the transmitter having a pre-amplifier and a power amplifier coupled to an output of the pre-amplifier, the control system comprising:

a signal input for receiving a detection signal representative of a pre-amplified transmission signal sensed at the output of the pre-amplifier by a detector;

a switching regulator control block configured to generate a switching supply control signal based on the received detection signal, the switching supply control signal comprising control values for a switched mode power supply configured to generate a supply voltage signal for the power amplifier in response to the switching supply control signal;

a power limit control block configured to generate a gain control signal based on an automatic gain control signal related to the pre-amplifier, the received detection signal, and a transmit power limit signal for limiting transmission power of the transmitter, the gain control signal being provided to the pre-amplifier for controlling gain in the pre-amplifier; and

a signal output for providing the switching supply control signal to the switched mode power supply;

wherein, in operation, the switching regulator control block communicates with the detector using the signal input and with the switched mode power supply using the signal output.

2. The control system of claim 1, wherein the switching regulator control block is configured to generate the switching supply control signal by applying a switching control transfer function to the received detection signal, the switching control transfer function having values determined based on a characterization of the response of the detector, control curves of the switched mode power supply, and a response of the power amplifier to input drive.

3. The control system of claim 2, wherein the switching regulator control block is configured to generate the switching supply control signal further based on a trim signal generated to compensate for component tolerances.

4. The control system of claim 1, wherein the switching regulator control block is implemented with a processor and the switching control transfer function is defined using one or more look-up tables.

5. The control system of claim 1, wherein the power limit control block is implemented with a processor and is configured to apply a power limiting transfer function defined using one or more look-up tables to generate the gain control signal.

6. The control system of claim 1, wherein the control values for the switched mode power supply are generated to hold the power amplifier in a state of constant compression.

7. The control system of claim 1, wherein the power management block further comprises a compensation control block configured to provide a gain correction signal based on the supply voltage signal, and wherein the gain correction signal is subtracted from the automatic gain control prior to providing the automatic gain control signal to the power limit control block.

8. A method of controlling a transmitter of a wireless device, the transmitter having a pre-amplifier and a power amplifier coupled to an output of the pre-amplifier, the method comprising:

receiving a detection signal representative of a pre-amplified transmission signal sensed at the output of the pre-amplifier by a detector;

generating a switching supply control signal based on the received detection signal, the switching supply control signal comprising control values for a switched mode power supply configured to generate a supply voltage signal for the power amplifier in response to the switching supply control signal;

generating a gain control signal based on an automatic gain control signal related to the pre-amplifier, the received detection signal, and a transmit power limit signal for limiting transmission power of the transmitter, the gain control signal being provided to the pre-amplifier for controlling gain in the pre-amplifier; and

providing the switching supply control signal to the switched mode power supply.

9. The method of claim 8, further comprising generating the switching supply control signal by applying a switching control transfer function to the received detection signal, the switching control transfer function having values determined based on a characterization of the response of the detector, control curves of the switched mode power supply, and a response of the power amplifier to input drive.

10. The method of claim 9, further comprising generating the switching supply control signal based on a trim signal generated to compensate for component tolerances.

11. The method of claim 8, wherein the switching supply control signal is generated by a processor and the switching control transfer function is defined in using one or more look-up tables.

12. The method of claim 8, wherein the gain control signal is generated by a processor, and the method further comprises applying a power limiting transfer function using one or more look-up tables to generate the gain control signal.

13. The method of claim 8, further comprising generating the control values for the switched mode power supply to hold the power amplifier in a state of constant compression.

14. The method of claim 8, further comprising generating a gain correction signal based on the supply voltage signal, and wherein the gain correction signal is subtracted from the automatic gain control signal prior to generating the gain control signal.

15. A computer-readable storage medium storing instructions executable by a processor coupled to the storage medium, the instructions, when executed by the processor, cause the processor to perform acts of a method of controlling a transmitter of a wireless device, the transmitter having a pre-amplifier and a power amplifier coupled to an output of the pre-amplifier, said acts comprising:

receiving a detection signal representative of a pre-amplified transmission signal sensed at the output of the pre-amplifier by a detector;

generating a switching supply control signal based on the received detection signal, the switching supply control signal comprising control values for a switched mode power supply configured to generate a supply voltage signal for the power amplifier in response to the switching supply control signal;

generating a gain control signal based on an automatic gain control signal related to the pre-amplifier, the received detection signal, and a transmit power limit signal for limiting transmission power of the transmitter, the gain control signal being provided to the pre-amplifier for controlling gain in the pre-amplifier; and

providing the switching supply control signal to the switched mode power supply.

16. The computer-readable storage medium of claim 15, wherein said acts further comprise generating the switching supply control signal by applying a switching control transfer function to the received detection signal, the switching control transfer function having values determined based on a characterization of the response of the detector, control curves of the switched mode power supply, and a response of the power amplifier to input drive.

17. The computer-readable storage medium of claim 16, wherein said acts further comprise generating the switching supply control signal based on a trim signal generated to compensate for component tolerances.

18. The computer-readable storage medium of claim 15, wherein said acts further comprise defining the switching control transfer function using one or more look-up tables.

19. The computer-readable storage medium of claim 15, wherein said acts further comprise applying a power limiting transfer function using one or more look-up tables to generate the gain control signal.

20. The computer-readable storage medium of claim 15, wherein said acts further comprise generating the control values for the switched mode power supply to hold the power amplifier in a state of constant compression.

21. The computer-readable storage medium of claim 15, wherein said acts further comprise generating a gain correction signal based on the supply voltage signal, and wherein the gain correction signal is subtracted from the automatic gain control signal prior to generating the gain control signal.