METHOD OF POWER AMPLIFIER SWITCHING POWER CONTROL USING POST POWER AMPLIFIER POWER DETECTION

• US 20120021704A1
• Filed: 07/23/2010
• Published: 01/26/2012
• Est. Priority Date: 07/23/2010
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Chan, Wen-Yen, Khan, Nasserullah, Chung, Ian Ka Yin, Bari, Hamza Mohaimeen
• Granted Patent: US 8,620,238 B2
• Time in Patent Office: Days
• US Class Current: 455/95
• 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 3/24 of transmitter output stages
• CPC Class Codes: H03G 11/00 Limiting amplitude; Limiting rate of change of amplitude ; Clipping in general
• 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 1/04 Circuits
• CPC Class Codes: H04B 2001/0416 having gain or transmission power control
• CPC Class Codes: H04B 2001/045 with means for improving efficiency

Abstract

Various embodiments described herein relate to a power management block and one or more amplification blocks 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, both of which are included in a selected one of the amplification blocks. 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 1n into account various characteristics of the transmitter components and control values. Post power amplifier transmission power is detected for input into the one or more feedback loops executed in the power management block. A controller for the power amplifier is design to stabilize the system with respect to gain expansion in the power amplifier.

Claims

1. A transmitter for a mobile device comprising:

a power amplifier for generating an amplified transmission signal;

a detector coupled to an output of the power amplifier and configured to provide a detected amplified transmission signal; and

a power management block comprising;

a switching regulator control block configured to generate a switching supply control signal based on the detected amplified transmission signal; and

a switched mode power supply coupled to the switching regulator control block and configured to generate a supply voltage signal for the power amplifier based on the switching supply control signal.

2. The transmitter of claim 1, wherein the switching regulator control block is configured to apply a switching control transfer function to the detected amplified transmission signal to generate the switching supply control signal.

3. The transmitter of claim 2, wherein the switching control transfer function is derived based on a characterization of the detector, control curves of the switched mode power supply, and a response of the power amplifier to input drive and supply voltage.

4. The transmitter of claim 2, wherein the switching regulator control block and the switched mode power supply are included in a switching regulator control loop, and the switching control transfer function has poles located to stabilize the switching regulator control loop for gain expansion in the power amplifier.

5. The transmitter of claim 4, wherein the poles of the switching control transfer function are further located to stabilize the switching regulator control loop for environmental or operating conditions of the power amplifier.

6. The transmitter of claim 1, wherein the switching regulator control block is configured to generate the switching supply control signal having control values for the switched mode power supply that cause clipping of the amplified transmission signal.

7. The transmitter of claim 1, wherein the transmitter comprises:

a plurality of power amplifiers; and

at least one switch configured to couple one of the plurality of power amplifiers to the detector to provide the detected amplified transmission signal.

8. A mobile device comprising:

a processor configured to control the operation of the mobile device;

a transmitter connected to the processor and configured to send and receive data, the transmitter comprising;

a power amplifier for generating an amplified transmission signal;

a detector coupled to an output of the power amplifier and configured to provide a detected amplified transmission signal; and

a power management block comprising a switching regulator control block configured to generate a switching supply control signal based on the detected amplified transmission signal; and

a switched mode power supply coupled to the switching regulator control block and configured to generate a supply voltage signal for the power amplifier based on the switching supply control signal.

9. The mobile device of claim 8, wherein the switching regulator control block is configured to apply a switching control transfer function to the detected amplified transmission signal to generate the switching supply control signal.

10. The mobile device of claim 9, wherein the switching control transfer function is derived based on a characterization of the detector, control curves of the switched mode power supply, and a response of the power amplifier to input drive and supply voltage.

11. The mobile device of claim 9, wherein the switching regulator control block and the switched mode power supply are included in a switching regulator control loop, and the switching control transfer function has poles located to stabilize the switching regulator control loop for gain expansion in the power amplifier.

12. The mobile device of claim 11, wherein the poles of the switching control transfer function are further located to stabilize the switching regulator control loop for environmental or operating conditions of the power amplifier.

13. The mobile device of claim 8, wherein the switching regulator control block is configured to generate the switching supply control signal having control values for the switched mode power supply that cause clipping of the amplified transmission signal.

14. The mobile device of claim 8, wherein the transmitter comprises:

a plurality of power amplifiers; and

at least one switch configured to coupled one of the plurality of power amplifiers to the detector to provide the detected amplified transmission signal.

15. A method of providing a supply voltage signal to a power amplifier, the method comprising:

generating an amplified transmission signal using the power amplifier;

detecting an output of the power amplifier using a detector to provide a detected amplified transmission signal;

generating a switching supply control signal based on the detected amplified transmission signal; and

generating the supply voltage signal by providing the switching supply control signal to a switched mode power supply.

16. The method of claim 15, wherein the method comprises applying a switching control transfer function to the detected amplified transmission signal to generate the switching supply control signal.

17. The method of claim 16, further comprising deriving the switching control transfer function based on a characterization of the detector, control curves of the switched mode power supply, and a response of the power amplifier to input drive and supply voltage.

18. The method of claim 16, wherein the method comprises deriving the switching control transfer function to have poles located to stabilize a switching regulator control loop for gain expansion in the power amplifier.

19. The method of claim 18, wherein the method comprises further deriving the switching control transfer function to have poles located to stabilize the switching regulator control loop for environmental or operating conditions of the power amplifier.

20. The method of claim 15, wherein the method comprises generating the switching supply control signal to have control values for the switched mode power supply that cause clipping of the amplified transmission signal.

21. The method of claim 15, further comprising coupling one of a plurality of power amplifiers to the detector to provide the detected amplified transmission signal.