Controlling a power amplifier to transition among amplifier operational classes according to at least an output signal waveform trajectory

• US 7,639,072 B2
• Filed: 12/12/2006
• Issued: 12/29/2009
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: ParkerVision, Inc.
• Original Assignee: ParkerVision, Inc.
• Inventors: Rawlins, Gregory S., Sorrells, David F., Rawlins, Michael W.
• Primary Examiner(s): Nguyen; Khanh V
• Application Number:
  US11/636,969
• Publication Number:
  US 20070090874A1
• Time in Patent Office: 1,113 Days
• Field of Search: 330/2, 330/10, 330/147, 330/124.R, 330/295, 455/127.1
• US Class Current: 330/2
• 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 1/0261 with control of the polarisation voltage or current, e.g. gliding Class A
• CPC Class Codes: H03F 1/0294 using vector summing of two or more constant amplitude phase-modulated signals
• CPC Class Codes: H03F 1/32 Modifications of amplifiers to reduce non-linear distortion by negative feedback H03F1/34
• CPC Class Codes: H03F 2200/102 A non-specified detector of a signal envelope being used in an amplifying circuit
• CPC Class Codes: H03F 2201/3206 Multiple channels are combined and amplified by only one amplifier
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03F 3/38 DC amplifiers with modulator at input and demodulator at output; Modulators or demodulators specially adapted for use in such amplifiers switched capacitor amplifiers H03F3/005
• 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

Abstract

Methods and systems for vector combining power amplification are disclosed herein. In one embodiment, a plurality of signals are individually amplified, then summed to form a desired time-varying complex envelope signal. Phase and/or frequency characteristics of one or more of the signals are controlled to provide the desired phase, frequency, and/or amplitude characteristics of the desired time-varying complex envelope signal. In another embodiment, a time-varying complex envelope signal is decomposed into a plurality of constant envelope constituent signals. The constituent signals are amplified equally or substantially equally, and then summed to construct an amplified version of the original time-varying envelope signal. Embodiments also perform frequency up-conversion.

Claims

1. An apparatus for at least RF power amplification, comprising:

means for generating a plurality of control signals;

means for generating a plurality of substantially constant envelope signals using at least said control signals and a frequency reference signal;

a power amplifier that amplifies and combines said substantially constant envelope signals to create an output signal; and

means for controlling said power amplifier to transition among amplifier operational classes according to at least waveform trajectory of said output signal.

2. The apparatus of claim 1, wherein said controlling means comprises:

means for causing said power amplifier to vary its amplifier class of operation according to changes in said waveform trajectory of said output signal.

3. The apparatus of claim 1, wherein said controlling means comprises:

means for causing said power amplifier to traverse from a switching amplifier to a substantially linear amplifier as a waveform envelope of said output signal decreases from its maximum value towards zero.

4. The apparatus of claim 1, wherein said controlling means comprises:

means for causing said power amplifier to traverse to a substantially linear amplifier at a zero crossing of a waveform envelope of said output signal.

5. The apparatus of claim 1, wherein said controlling means comprises:

means for causing said power amplifier to traverse to a higher amplifier operational class as a waveform envelope of said output signal increases from a zero crossing of said waveform envelope.

6. The apparatus of claim 1, wherein said controlling means comprises:

means for controlling phases of said substantially constant envelope signals to cause said power amplifier to transition among amplifier operational classes.

7. The apparatus of claim 1, wherein said controlling means comprises:

means for controlling amplitudes of signals input to said power amplifier to cause said power amplifier to transition among amplifier operational classes.

8. The apparatus of claim 7, where said amplitude controlling means comprises:

means for controlling amplitudes of signals input to said power amplifier, pursuant to a transfer function, to cause said power amplifier to transition among amplifier operational classes.

9. The apparatus of claim 1, where said controlling means comprises:

means for biasing inputs to said power amplifier to cause said power amplifier to transition among amplifier operational classes.

10. The apparatus of claim 9, where said biasing means comprises:

means for biasing inputs to said power amplifier, pursuant to a transfer function, to cause said power amplifier to transition among amplifier operational classes.

11. The apparatus of claim 1, wherein said controlling means comprises at least one of(a)-(c):

(a) means for controlling phases of said substantially constant envelope signals to cause said power amplifier to transition among amplifier operational classes;

(b) means for controlling amplitudes of signals input to said power amplifier to cause said power amplifier to transition among amplifier operational classes; and

(c) means for biasing inputs to said power amplifier to cause said power amplifier to transition among amplifier operational classes.

12. The apparatus of claim 1, wherein said controlling means comprises:

means for causing said power amplifier to transition to a substantially linear amplifier by controlling drive level and bias of said power amplifier such that an output current conduction angle is equal to 360 degrees.

13. The apparatus of claim 1, wherein said controlling means comprises:

means for causing said power amplifier to transition to a class AB amplifier by controlling drive level and bias of said power amplifier such that an output current conduction angle is greater than 180 degrees and less than 360 degrees.

14. The apparatus of claim 1, wherein said controlling means comprises:

means for causing said power amplifier to transition to a class B amplifier by controlling drive level and bias of said power amplifier such that an output current conduction angle is substantially equal to 180 degrees.

15. The apparatus of claim 1, wherein said controlling means comprises:

means for causing said power amplifier to transition to a class C amplifier by controlling drive level and bias of said power amplifier such that an output current conduction angle is less than 180 degrees.

16. The apparatus of claim 1, wherein said controlling means comprises:

means for causing said power amplifier to transition to a class D amplifier by controlling drive level and bias of said power amplifier such that said power amplifier is operated in switch mode.

17. The apparatus of claim 1, wherein said controlling means comprises:

means for causing said power amplifier to transition to a switching amplifier by controlling said power amplifier to generate a Pulse Width Modulated (PWM) output signal.

18. The apparatus of claim 1, wherein said controlling means comprises:

means for controlling said power amplifier to transition among amplifier operational classes pursuant to a transfer function that varies within a spectrum of magnitude to phase shift transform functions.

19. The apparatus of claim 1, wherein said controlling means comprises:

means for controlling said power amplifier to transition from a substantially linear amplifier to a switching amplifier.

20. A method for at least RF power amplification, comprising:

generating a plurality of control signals;

generating a plurality of substantially constant envelope signals using at least said control signals and a frequency reference signal;

amplifying and combining said substantially constant envelope signals using a power amplifier to create an output signal; and

controlling said power amplifier to transition among amplifier operational classes according to at least waveform trajectory of said output signal.

21. The method of claim 20, wherein said controlling step comprises:

causing said power amplifier to vary its amplifier class of operation according to changes in said waveform trajectory of said output signal.

22. The method of claim 20, wherein said controlling step comprises:

causing said power amplifier to traverse from a switching amplifier to a substantially linear amplifier as a waveform envelope of said output signal decreases from its maximum value towards zero.

23. The method of claim 20, wherein said controlling step comprises:

causing said power amplifier to traverse to a substantially linear amplifier at a zero crossing of a waveform envelope of said output signal.

24. The method of claim 20, wherein said controlling step comprises:

causing said power amplifier to traverse to a higher amplifier operational class as a waveform envelope of said output signal increases from a zero crossing of said waveform envelope.

25. The method of claim 20, wherein said controlling step comprises:

controlling phases of said substantially constant envelope signals to cause said power amplifier to transition among amplifier operational classes.

26. The method of claim 20, wherein said controlling step comprises:

controlling amplitudes of signals input to said power amplifier to cause said power amplifier to transition among amplifier operational classes.

27. The method of claim 26, where said amplitude controlling step comprises:

controlling amplitudes of signals input to said power amplifier, pursuant to a transfer function, to cause said power amplifier to transition among amplifier operational classes.

28. The method of claim 20, where said controlling step comprises:

biasing inputs to said power amplifier to cause said power amplifier to transition among amplifier operational classes.

29. The method of claim 28, where said biasing means comprises:

biasing inputs to said power amplifier, pursuant to a transfer function, to cause said power amplifier to transition among amplifier operational classes.

30. The method of claim 20, wherein said controlling step comprises at least one of (a)-(c):

(a) controlling phases of said substantially constant envelope signals to cause said power amplifier to transition among amplifier operational classes;

(b) controlling amplitudes of signals input to said power amplifier to cause said power amplifier to transition among amplifier operational classes; and

(c) biasing inputs to said power amplifier to cause said power amplifier to transition among amplifier operational classes.

31. The method of claim 20, wherein said controlling step comprises:

causing said power amplifier to transition to a substantially linear amplifier by controlling drive level and bias of said power amplifier such that an output current conduction angle is equal to 360 degrees.

32. The method of claim 20, wherein said controlling step comprises:

causing said power amplifier to transition to a class AB amplifier by controlling drive level and bias of said power amplifier such that an output current conduction angle is greater than 180 degrees and less than 360 degrees.

33. The method of claim 20, wherein said controlling step comprises:

causing said power amplifier to transition to a class B amplifier by controlling drive level and bias of said power amplifier such that an output current conduction angle is substantially equal to 180 degrees.

34. The method of claim 20, wherein said controlling step comprises:

causing said power amplifier to transition to a class C amplifier by controlling drive level and bias of said power amplifier such that an output current conduction angle is less than 180 degrees.

35. The method of claim 20, wherein said controlling step comprises:

causing said power amplifier to transition to a class D amplifier by controlling drive level and bias of said power amplifier such that said power amplifier is operated in switch mode.

36. The method of claim 20, wherein said controlling step comprises:

causing said power amplifier to transition to a switching amplifier by controlling said power amplifier to generate a Pulse Width Modulated (PWM) output signal.

37. The method of claim 20, wherein said controlling step comprises:

controlling said power amplifier to transition among amplifier operational classes pursuant to a transfer function that varies within a spectrum of magnitude to phase shift transform functions.

38. The method of claim 20, wherein said controlling step comprises:

controlling said power amplifier to transition from a substantially linear amplifier to a switching amplifier.

39. A power amplifier, comprising:

a transfer function module to receive I and Q data, and to generate amplitude and phase information;

circuitry to generate substantially constant envelope signals from at least said amplitude and phase information; and

an amplifier output stage to amplify and combine said substantially constant envelope signals to generate an output signal;

wherein said amplifier output stage is controlled to transition among amplifier operational classes according to at least waveform trajectory of said output signal.

40. The power amplifier of claim 39, wherein said amplifier output stage is controlled to traverse from a switching amplifier to a substantially linear amplifier as a waveform envelope of said output signal decreases from its maximum value towards zero.

41. The power amplifier of claim 39, wherein said amplifier output stage is controlled to traverse to a substantially linear amplifier at a zero crossing of a waveform envelope of said output signal.

42. The power amplifier of claim 39, wherein said amplifier output stage is controlled to traverse to a higher amplifier operational class as a waveform envelope of said output signal increases from a zero crossing of said waveform envelope.

43. The power amplifier of claim 39, wherein phases of said substantially constant envelope signals are controlled to cause said amplifier output stage to transition among amplifier operational classes.

44. The power amplifier of claim 39, wherein amplitudes of signals input to said amplifier output stage are controlled to cause said amplifier output stage to transition among amplifier operational classes.

45. The power amplifier of claim 44, where said transfer function module operates according to a transfer function to control amplitudes of signals input to said amplifier output stage, to cause said amplifier output stage to transition among amplifier operational classes.

46. The power amplifier of claim 39, where inputs to said amplifier output stage are biased to cause said amplifier output stage to transition among amplifier operational classes.

47. The power amplifier of claim 46, where said transfer function module operates according to a transfer function to bias inputs to said amplifier output stage, to thereby cause said amplifier output stage to transition among amplifier operational classes.

48. The power amplifier of claim 39, wherein said amplifier output stage is controlled to transition to a substantially linear amplifier by controlling drive level and bias of said amplifier output stage such that an output current conduction angle is equal to 360 degrees.

49. The power amplifier of claim 39, wherein said amplifier output stage is controlled to transition to a class AB amplifier by controlling drive level and bias of said amplifier output stage such that an output current conduction angle is greater than 180 degrees and less than 360 degrees.

50. The power amplifier of claim 39, wherein said amplifier output stage is controlled to transition to a class B amplifier by controlling drive level and bias of said amplifier output stage such that an output current conduction angle is substantially equal to 180 degrees.

51. The power amplifier of claim 39, wherein said amplifier output stage is controlled to transition to a class C amplifier by controlling drive level and bias of said amplifier output stage such that an output current conduction angle is less than 180 degrees.

52. The power amplifier of claim 39, wherein said amplifier output stage is controlled to transition to a class D amplifier by controlling drive level and bias of said amplifier output stage such that said amplifier output stage is operated in switch mode.

53. The power amplifier of claim 39, wherein said amplifier output stage is controlled to transition to a switching amplifier by controlling said amplifier output stage to generate a Pulse Width Modulated (PWM) output signal.

54. The power amplifier of claim 39, wherein said amplifier output stage is controlled to transition among amplifier operational classes pursuant to a transfer function that varies within a spectrum of magnitude to phase shift transform functions.

55. The power amplifier of claim 39, wherein said amplifier output stage is controlled to transition from a substantially linear amplifier to a switching amplifier.