Method and system for providing power management in a radio frequency power amplifier using adaptive envelope tracking

• US 6,914,487 B1
• Filed: 04/17/2003
• Issued: 07/05/2005
• Est. Priority Date: 04/19/2002
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Maksimovic, Dragan, Li, Yushan, Doyle, James T.
• Primary Examiner(s): Choe, Henry
• Application Number:
  US10/417,566
• Time in Patent Office: 810 Days
• Field of Search: 330/297, 330/129, 330/136, 330/298, 330/285, 330/296, 330/207.P
• US Class Current: 330/297
• CPC Class Codes: H03F 1/0222 by using a signal derived from the input signal
• CPC Class Codes: H03F 1/0233 by using a signal derived from the output signal, e.g. bootstrapping the voltage supply
• CPC Class Codes: H03F 2200/102 A non-specified detector of a signal envelope being used in an amplifying circuit

Abstract

A method for providing power management in a radio frequency power amplifier using adaptive envelope tracking is provided that includes receiving an input voltage. A power control signal is received. A feedback signal is received. An amplifier input signal is received. From the input voltage, a regulated power supply signal is generated based on the power control signal, the feedback signal, and the amplifier input signal.

Claims

1. A method for providing power management in a radio frequency power amplifier using adaptive envelope tracking, comprising:

receiving an input voltage;

receiving a power control signal;

receiving a feedback signal;

receiving an amplifier input signal; and

generating from the input voltage a regulated power supply signal using the power control signal, the feedback signal, and the amplifier input signal.

2. The method of claim 1, further comprising providing the regulated power supply signal to a power amplifier.

3. The method of claim 2, further comprising:

receiving the regulated power supply signal at the power amplifier;

receiving a radio frequency input signal at the power amplifier; and

generating at the power amplifier a radio frequency output signal based on the radio frequency input signal.

4. The method of claim 3, further comprising providing the radio frequency output signal to an antenna for transmission over a wireless interface.

5. The method of claim 3, receiving a feedback signal comprising receiving the feedback signal from a directional coupler operable to provide the radio frequency output signal as the feedback signal.

6. The method of claim 3, receiving an amplifier input signal comprising receiving the amplifier input signal from a directional coupler operable to provide the radio frequency input signal as the amplifier input signal.

7. The method of claim 1, receiving an input voltage comprising receiving the input voltage from a power source, the power source comprising a battery.

8. The method of claim 1, the amplifier input signal comprising a signal of about 1 MHz to about 5 MHz.

9. A method for providing power management in a radio frequency power amplifier using adaptive envelope tracking, comprising:

receiving an input voltage;

receiving a power control signal;

receiving a digital feedback signal;

receiving a digital amplifier input signal;

converting the digital amplifier input signal into an analog amplifier input signal;

converting the digital feedback signal into an analog feedback signal; and

generating from the input voltage a regulated power supply signal using the power control signal, the analog feedback signal, and the analog amplifier input signal.

10. The method of claim 9, further comprising:

providing the regulated power supply signal to a power amplifier;

receiving the regulated power supply signal at the power amplifier;

receiving a radio frequency input signal at the power amplifier; and

generating at the power amplifier a radio frequency output signal based on the radio frequency input signal.

11. The method of claim 9, receiving an input voltage comprising receiving the input voltage from a power source, the power source comprising a battery.

12. The method of claim 9, the analog amplifier input signal comprising a signal of about 1 MHz to about 5 MHz.

13. A system for providing power management in a radio frequency power amplifier using adaptive envelope tracking, comprising:

a power amplifier operable to generate a radio frequency output signal based on a radio frequency input signal; and

a power converter coupled to the power amplifier, the power converter operable to receive an input voltage, a power control signal, a feedback signal and an amplifier input signal and to generate from the input voltage a regulated power supply signal for the power amplifier using the power control signal, the feedback signal, and the amplifier input signal.

14. The system of claim 13, further comprising a directional coupler operable to provide the radio frequency output signal from the power amplifier to the power converter as the feedback signal.

15. The system of claim 13, further comprising a directional coupler operable to provide the radio frequency input signal to the power converter as the amplifier input signal.

16. The system of claim 13, further comprising a power source.

17. The system of claim 16, the power source comprising a battery.

18. The system of claim 13, further comprising an antenna coupled to the power amplifier, the antenna operable to receive the radio frequency output signal from the power amplifier and to transmit the radio frequency output signal over a wireless interface.

19. The system of claim 13, further comprising a soft limiter coupled to the power amplifier, the soft limiter operable to receive an input signal, to remove amplitude information from the input signal and to provide phase information from the input signal to the power amplifier.

20. The system of claim 19, further comprising:

a differencing node coupled to the power converter;

a first envelope detector coupled to the differencing node, the first envelope detector operable to receive the input signal, to remove phase information from the input signal and to provide amplitude information from the input signal to the differencing node as the amplifier input signal;

an attenuator coupled to the power amplifier, the attenuator operable to receive the radio frequency output signal and to attenuate the radio frequency output signal;

a second envelope detector coupled to the differencing node and to the attenuator, the second envelope detector operable to receive the attenuated output signal, to remove phase information from the attenuated output signal and to provide amplitude information from the attenuated output signal to the differencing node as the feedback signal; and

the differencing node operable to determine a difference between the amplifier input signal and the feedback signal and to provide the difference to the power converter.

21. A system for providing power management in a radio frequency power amplifier using adaptive envelope tracking, comprising:

a power amplifier operable to generate a radio frequency output signal based on a radio frequency input signal; and

a power regulator coupled to the power amplifier, the power regulator operable to receive a power source signal, a power control signal, and an envelope signal and to generate from the power source signal a regulated power supply signal for the power amplifier based on the power control signal and the envelope signal.

22. The system of claim 21, the power regulator comprising an adaptive envelope tracking (AET) controller operable to receive the power control signal and the envelope signal and to generate first, second and third output signals.

23. The system of claim 22, the power regulator further comprising an operational amplifier coupled to the AET controller, the operational amplifier operable to receive the first output signal and a feedback signal and to generate the regulated power supply signal based on the first output signal and the feedback signal.

24. The system of claim 23, the power regulator further comprising:

a first transistor coupled to the AET controller, the first transistor operable to receive the second output signal and the power source signal;

a second transistor coupled to the AET controller and to the first transistor, the second transistor operable to receive the third output signal, the first and second transistors operable to generate a buck signal; and

a synchronous buck coupled to the first and second transistors and to the operational amplifier, the synchronous buck operable to receive the buck signal.

25. The system of claim 21, further comprising an antenna coupled to the power amplifier, the antenna operable to receive the radio frequency output signal from the power amplifier and to transmit the radio frequency output signal over a wireless interface.