Method and apparatus for providing adaptive supply voltage control of a power amplifier

• US 20080003962A1
• Filed: 06/30/2006
• Published: 01/03/2008
• Est. Priority Date: 06/30/2006
• Status: Abandoned Application

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Ngai, Wai Lim
• Application Number:
  US11/479,955
• Publication Number:
  US 20080003962A1
• Time in Patent Office: Days
• US Class Current: 455/179.1
• 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 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 1/0211 with control of the supply voltage or current
• CPC Class Codes: H03F 2200/321 Use of a microprocessor in an amplifier circuit or its control circuit
• CPC Class Codes: H03F 2200/465 Power sensing
• CPC Class Codes: H03F 2200/471 the voltage being sensed
• CPC Class Codes: H03F 3/24 of transmitter output stages
• 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 2001/045 with means for improving efficiency

Abstract

An approach is provided for adaptive supply voltage control of a power amplifier. A voltage detector detects a voltage swing, and a power detector detects power. A controller is coupled to the voltage detector and the power detector. The controller receives a signal specifying a required output power and determines, using the detected voltage swing and the detected power, a supply rail voltage corresponding to the required output power at a particular loading condition. A converter applies the determined supply rail voltage for generating the required output power.

Claims

1. An apparatus comprising:

a voltage detector configured to detect a voltage swing;

a power detector configured to detect power;

a controller coupled to the voltage detector and the power detector, the controller being configured to receive a signal specifying a required output power and to determine, using the detected voltage swing and the detected power, a supply rail voltage corresponding to the required output power at a particular loading condition; and

a converter configured to apply the determined supply rail voltage for generating the required output power.

2. An apparatus according to claim 1, further comprising:

a first DC feed and a second DC feed collectively representing the particular loading condition and being coupled to the converter;

a driver stage circuit coupled to the first DC feed, the driver stage circuit being configured to receive the supply rail voltage; and

a final stage circuit coupled to the second DC feed, the driver stage circuit being configured to receive the supply rail voltage.

3. An apparatus according to claim 2, further comprising:

a first matching network configured to receive an input signal to be amplified, the first matching network being coupled to the driver stage circuit;

a second matching network coupled to the first DC feed and the final stage circuit; and

a third matching network coupled to the second DC feed and the power detector.

4. An apparatus according to claim 2, wherein the driver stage circuit includes a first transistor, and the second biasing circuit includes a second transistor, the apparatus further comprising:

a first biasing circuit coupled to the driver stage circuit to bias the first transistor; and

a second biasing circuit coupled to the final stage circuit to bias the second transistor.

5. An apparatus according to claim 4, wherein the detected voltage swing corresponds to the second transistor.

6. An apparatus according to claim 1, further comprising:

an output power sampler configured to generate the power to the power detector.

7. An apparatus according to claim 1, wherein the particular loading condition represents a variable antenna load under a particular condition.

8. An apparatus according to claim 1, wherein the controller includes a digital signal processor (DSP), a real-time software, or an analog-controller.

9. An apparatus according to claim 1, wherein the converter is configured to provide DC-to-DC voltage conversion.

10. An apparatus according to claim 1, wherein the voltage detector is configured to provide peak envelope detection or root mean square (RMS) power detection.

11. A system comprising the apparatus of claim 1, the system further comprising:

a transceiver coupled to the apparatus, wherein the apparatus is configured to amplify a voice signal, the transceiver being configured to transmit the amplified voice signal over a wireless network.

12. A method comprising:

receiving a signal specifying a required output power;

detecting a voltage swing;

detecting power;

determining, using the detected voltage swing and the detected power, a supply rail voltage corresponding to the required output power at a particular loading condition; and

applying the determined supply rail voltage to generate the required output power.

13. A method according to claim 12, wherein the determined supply rail voltage is applied to a driver stage circuit over a first DC feed, and to a final stage circuit over second DC feed.

14. A method according to claim 12, further comprising:

generating a first bias signal to bias the driver stage circuit; and

generating a second bias signal to bias the final stage circuit.

15. A method according to claim 14, wherein the detected voltage swing corresponds to the final stage circuit.

16. A method according to claim 12, further comprising:

generating the power by a output power sampler; and

supplying the power to a power detector for the detection of the power.

17. A method according to claim 12, wherein the particular loading condition represents a variable antenna load under a particular condition.

18. A method according to claim 12, wherein the determining step is performed by a controller that includes a digital signal processor (DSP), a real-time software, or an analog-controller.

19. A method according to claim 12, wherein the applying step is performed by a converter that is configured to provide DC-to-DC voltage conversion.

20. A method according to claim 12, wherein the step of detecting the voltage swing is performed by a voltage detector that is configured to provide peak envelope detection or root mean square (RMS) power detection.

21. An apparatus comprising:

means for receiving a signal specifying a required output power;

means for detecting a voltage swing;

means for detecting power;

means for determining, using the detected voltage swing and the detected power, a supply rail voltage corresponding to the required output power at a particular loading condition; and

means for applying the determined supply rail voltage to generate the required output power.

22. A system comprising the apparatus of claim 21, the system further comprising:

means for generating a voice signal to be amplified by the apparatus; and

transceiving means for transmitting the voice signal over a radio communication channel.