Systems, methods, and apparatuses for linear polar transmitters

• US 7,860,466 B2
• Filed: 05/25/2007
• Issued: 12/28/2010
• Est. Priority Date: 06/04/2006
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Chang-Ho, Chang, Jaejoon, Kim, Haksun, Woo, Wangmyong
• Primary Examiner(s): Pan; Yuwen
• Assistant Examiner(s): AKINYEMI, AJIBOLA A
• Application Number:
  US11/754,112
• Publication Number:
  US 20070298734A1
• Time in Patent Office: 1,313 Days
• Field of Search: 455/114.3
• US Class Current: 455/114.3
• CPC Class Codes: H03F 1/0211 with control of the supply voltage or current
• CPC Class Codes: H03F 1/3282 Acting on the phase and the amplitude of the input signal
• CPC Class Codes: H03F 2200/324 An amplitude modulator or demodulator being used in the amplifier circuit
• CPC Class Codes: H03F 2200/393 A measuring circuit being coupled to the output of an amplifier
• CPC Class Codes: H03F 2200/504 the supply voltage or current being continuously controlled by a controlling signal, e.g. the controlling signal of a transistor implemented as variable resistor in a supply path for, an IC-block showed amplifier
• CPC Class Codes: H04L 27/361 Modulation using a single or unspecified number of carriers, e.g. with separate stages of phase and amplitude modulation
• CPC Class Codes: H04L 27/368 adaptive predistortion

Abstract

Systems and methods are disclosed for providing a linear polar transmitter. The systems and methods may include generating an input amplitude signal and an input phase signal, where the input amplitude signal and the input phase signal are orthogonal components of an input signal, and where the input amplitude signal and the input phase signal are generated on respective first and second signal paths. The systems and methods may also include processing the input amplitude signal along the first signal path using an amplitude error signal to generate a predistorted amplitude signal, and processing the input phase signal along the second signal path using an phase error signal to generate a predistorted phase signal. The systems and methods may also include providing the predistorted amplitude signal along the first signal path and the predistorted phase signal along the second signal path to a power amplifier to generate an output signal, where the amplitude error signal is generated from a comparison of at least an amplitude portion of the output signal with the predistorted amplitude signal and where the phase error signal is generated from a comparison of at least a phase portion of the output signal with the predistorted phase signal.

Claims

1. A method for providing a linear polar transmitter, comprising:

generating an analog input amplitude signal and an analog input phase signal, wherein the input amplitude signal and the input phase signal are orthogonal components of a system input signal, and wherein the input amplitude signal and the input phase signal are generated on respective first and second signal paths;

processing, in analog, the input amplitude signal along the first signal path using an analog amplitude error signal to generate an analog predistorted amplitude signal;

processing, in analog, the input phase signal along the second signal path using an analog phase error signal to generate an analog predistorted phase signal; and

providing the predistorted amplitude signal along the first signal path and the predistorted phase signal along the second signal path to a power amplifier to generate an output signal,

wherein the amplitude error signal is generated from a first comparison in analog of at least an amplitude portion of the output signal with the predistorted amplitude signal and wherein the phase error signal is generated from a second comparison in analog of at least a phase portion of the output signal with the predistorted phase signal,

wherein the amplitude error signal generated from the first comparison is combined directly by a multiplier with the input amplitude signal along the first signal path to generate the predistorted amplitude signal that is provided to the power amplifier,

wherein the phase error signal generated from the second comparison is combined directly by a phase adder with the input phase signal along the second signal path to generate the predistorted phase signal that is provided to the power amplifier.

2. The method of claim 1, wherein the input amplitude signal and the amplitude error signal are combined directly by the multiplier multiplying the input amplitude signal with the amplitude error signal.

3. The method of claim 1, wherein the input phase signal and the phase error signal are combined directly by the phase adder adding the input phase signal with the phase error signal.

4. The method of claim 1, wherein generating an input amplitude signal and an input phase signal includes generating an input amplitude vector on the first signal path and an input phase vector on the second signal path.

5. The method of claim 1, wherein the output signal is an analog signal.

6. The method of claim 1, wherein the amplitude error signal includes even-order amplitude distortion terms, and wherein the phase error signal includes even-order phase distortion terms.

7. The method of claim 1, wherein the amplitude error signal includes an approximate inverse of a gain of the power amplifier.

8. The method of claim 1, wherein the amplitude portion of the output signal is determined using an envelope detector applied to the output signal, and wherein the phase portion of the output signal is determined using an amplitude limiter applied to the output signal.

9. The method of claim 1, wherein the amplitude error signal is determined by dividing the predistorted amplitude signal by the amplitude portion of the output signal, and wherein the phase error signal is determined by multiplying the predistorted phase signal by the phase portion of the output signal.

10. A system for a linear polar transmitter, comprising:

a first predistortion module that processes, in analog, an analog input amplitude signal along a first signal path using an analog inverse amplitude error signal to generate an analog predistorted amplitude signal;

a second predistortion module that processes, in analog, an analog input phase signal along a second signal path using an analog inverse phase error signal to generate an analog predistorted phase signal, wherein the input amplitude signal and the input phase signal are orthogonal components of a system input signal; and

a power amplifier that receives the predistorted amplitude signal along the first signal path and the predistorted phase signal along the second signal path and generates an output signal based upon the predistorted amplitude signal and the predistorted phase signal, wherein the amplitude error signal is generated from a first comparison in analog of at least an amplitude portion of the output signal with the predistorted amplitude signal and wherein the phase error signal is generated from a second comparison in analog of at least a phase portion of the output signal with the predistorted phase signal,

wherein the amplitude error signal generated from the first comparison is combined directly by a multiplier with the input amplitude signal along the first signal path to generate the predistorted amplitude signal that is provided to the power amplifier,

wherein the phase error signal generated from the second comparison is combined directly by a phase adder with the input phase signal along the second signal path to generate the predistorted phase signal that is provided to the power amplifier.

11. The system of claim 10, wherein the input amplitude signal and the amplitude error signal are combined directly by multiplying, via the multiplier, the input amplitude signal with the inverse amplitude error signal.

12. The system of claim 10, wherein the input phase signal and the phase error signal are combined directly by adding, via the phase adder, the input phase signal with the inverse phase error signal.

13. The system of claim 10, wherein the input amplitude signal is an input amplitude vector and wherein the input phase signal is an input phase vector.

14. The system of claim 10, wherein the output signal is an analog signal.

15. The system of claim 10, wherein the amplitude error signal includes even-order amplitude distortion terms, and wherein the phase error signal includes low-frequency, even-order phase distortion terms.

16. The system of claim 10, wherein the amplitude error signal includes an approximate inverse of a gain of the power amplifier.

17. The system of claim 10, wherein the amplitude portion of the output signal is determined using an envelope detector applied to the output signal, and wherein the phase portion of the output signal is determined using an amplitude limiter applied to the output signal.

18. The system of claim 17, wherein the amplitude error signal is determined by dividing the predistorted amplitude signal by the amplitude portion of the output signal, and wherein the phase error signal is determined by multiplying the predistorted phase signal by the phase portion of the output signal.

19. A system for providing a linear polar transmitter, comprising:

first means for processing, in analog, an analog input amplitude signal along a first signal path using an analog inverse amplitude error signal to generate an analog predistorted amplitude signal;

second means for processing, in analog, an analog input phase signal along a second signal path using an analog inverse phase error signal to generate an analog predistorted phase signal, wherein the input amplitude signal and the input phase signal are orthogonal components of a system input signal; and

a power amplifier that receives the predistorted amplitude signal along the first signal path and the predistorted phase signal along the second signal path and generates an output signal based upon the predistorted amplitude signal and the predistorted phase signal, wherein the amplitude error signal is generated from a first comparison in analog of at least an amplitude portion of the output signal with the predistorted amplitude signal and wherein the phase error signal is generated from a second comparison in analog of at least a phase portion of the output signal with the predistorted phase signal,

wherein the amplitude error signal generated from the first comparison is combined directly by a multiplier with the input amplitude signal along the first signal path to generate the predistorted amplitude signal that is provided to the power amplifier,

wherein the phase error signal generated from the second comparison is combined directly by a phase adder with the input phase signal along the second signal path to generate the predistorted phase signal that is provided to the power amplifier.

20. The system of claim 19, wherein the input amplitude signal and the amplitude error signal are combined directly by the multiplier multiplying the input amplitude signal with the inverse amplitude error signal, and wherein the input phase signal and the phase error signal are combined directly by the phase adder adding the input phase signal with the inverse phase error signal.