Polar transmitter having a dynamically controlled voltage regulator and method for operating same

• US 20080009248A1
• Filed: 07/10/2006
• Published: 01/10/2008
• Est. Priority Date: 07/10/2006
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: Rozenblit, Dmitriy, Sowlati, Tirdad, Agahi, Darioush, Damgaard, Morten
• Granted Patent: US 7,764,055 B2
• Time in Patent Office: Days
• US Class Current: 455/127.1
• CPC Class Codes: H03F 1/0227 using supply converters
• CPC Class Codes: H03G 3/3047 for intermittent signals, e.g. burst signals
• CPC Class Codes: H04B 1/04 Circuits
• CPC Class Codes: H04B 2001/0416 having gain or transmission power control
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

A supply voltage controlled power amplifier includes a power amplifier, a closed power control loop configured to generate a power control signal, and a voltage regulator coupled to the power control loop, the voltage regulator including a first regulator stage, a second regulator stage, and a peak detector, wherein an output of the second regulator stage is applied as a feedback signal to the first regulator stage and wherein an output of the first regulator stage is decreased to a level consistent with an output of the power amplifier and an additional operating buffer amount.

Claims

1. A method for dynamically controlling the power output of a power amplifier, comprising:

providing a radio frequency (RF) signal to a power amplifier;

generating a power control signal in a closed power control loop;

providing the power control signal to a first voltage regulator;

providing the power control signal to a second voltage regulator;

providing a peak detector located between the first voltage regulator and the second voltage regulator; and

providing an output of the second voltage regulator as a feedback signal to the first voltage regulator, wherein an output of the first voltage regulator is decreased to a level consistent with an output of the power amplifier and an additional operating buffer amount.

2. The method of claim 1, further comprising implementing the first voltage regulator as a switching voltage regulator.

3. The method of claim 1, further comprising implementing the second voltage regulator as a linear voltage regulator.

4. The method of claim 2, further comprising using the feedback signal to dynamically control the switching voltage regulator.

5. The method of claim 4, further comprising using the feedback signal to dynamically control the linear voltage regulator.

6. The method of claim 1, wherein after a power ramp-up period, the output of the first voltage regulator only ramps down.

7. The method of claim 1, further comprising locating the first voltage regulator and the second voltage regulator in the closed power control loop.

8. The method of claim 6, further comprising:

comparing an output of the second voltage regulator with a predetermined threshold to determine whether the output of the second voltage regulator exceeds the predetermined threshold; and

if the output of the second voltage regulator exceeds the predetermined threshold bypassing the first voltage regulator.

9. A supply voltage controlled power amplifier, comprising:

a power amplifier;

a closed power control loop configured to generate a power control signal; and

a voltage regulator coupled to the power control loop, the voltage regulator comprising a first regulator stage, a second regulator stage, and a peak detector, wherein an output of the second regulator stage is applied as a feedback signal to the first regulator stage and wherein an output of the first regulator stage is decreased to a level consistent with an output of the power amplifier and an additional operating buffer amount.

10. The supply voltage controlled power amplifier of claim 9, wherein the first regulator stage is a switching voltage regulator having a bandwidth narrower than a bandwidth of the second regulator stage.

11. The supply voltage controlled power amplifier of claim 10, wherein the second regulator stage is a linear voltage regulator having a bandwidth wider than a bandwidth of the first regulator stage.

12. The supply voltage controlled power amplifier of claim 10, wherein the feedback signal dynamically controls the switching voltage regulator.

13. The supply voltage controlled power amplifier of claim 11, wherein the feedback signal dynamically controls the linear voltage regulator.

14. The supply voltage controlled power amplifier of claim 9, wherein after a power ramp-up period, the output of the first voltage regulator only ramps down.

15. The supply voltage controlled power amplifier of claim 9, wherein the first regulator stage and the second regulator stage are located in the closed power control loop.

16. The supply voltage controlled power amplifier of claim 14, further comprising:

a comparator for comparing an output of the second voltage regulator with a predetermined threshold to determine whether the output of the second voltage regulator exceeds the predetermined threshold; and

a bypass circuit for bypassing the first regulator stage if the output of the second voltage regulator exceeds the predetermined threshold.

17. A portable transceiver, comprising:

a transceiver for transmitting and receiving a radio frequency (RF) signal;

a power amplifier;

a closed power control loop configured to generate a power control signal; and

a voltage regulator coupled to the power control loop, the voltage regulator comprising a first regulator stage, a second regulator stage, and a peak detector, wherein an output of the second regulator stage is applied as a feedback signal to the first regulator stage and wherein an output of the first regulator stage is decreased to a level consistent with an output of the power amplifier and an additional operating buffer amount.

18. The portable transceiver of claim 17, wherein the first regulator stage is a switching voltage regulator having a bandwidth narrower than a bandwidth of the second regulator stage.

19. The portable transceiver of claim 17, wherein the second regulator stage is a linear voltage regulator having a bandwidth wider than a bandwidth of the first regulator stage.

20. The portable transceiver of claim 18, wherein the feedback signal dynamically controls the switching voltage regulator.

21. The portable transceiver of claim 17, wherein after a power ramp-up period, the output of the first voltage regulator only ramps down.

22. The portable transceiver of claim 21, wherein the first regulator stage and the second regulator stage are located in the closed power control loop.

23. The portable transceiver of claim 21, further comprising:

a comparator for comparing an output of the second voltage regulator with a predetermined threshold to determine whether the output of the second voltage regulator exceeds the predetermined threshold; and

a bypass circuit for bypassing the first regulator stage if the output of the second voltage regulator exceeds the predetermined threshold.