Input Amplitude Modulated Outphasing with an Unmatched Combiner

• US 20150295552A1
• Filed: 11/16/2012
• Published: 10/15/2015
• Est. Priority Date: 11/16/2012
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Inventors: Felgentreff, Tilman, Abou-Chahine, Zeid
• Granted Patent: US 9,484,874 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H03F 1/0294 using vector summing of two or more constant amplitude phase-modulated signals
• CPC Class Codes: H03F 2203/21142 Output signals of a plurality of power amplifiers are parallel combined to a common output
• CPC Class Codes: H03F 2203/21157 A filter circuit being added at the output of a power amplifier stage
• CPC Class Codes: H03F 3/245 with semiconductor devices only
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602

Abstract

An amplifier system is disclosed, configured to apply a signal component separator algorithm such that the first phase modulated signal and the second phase modulated signal are allowed to take on several continuous amplitude levels in order to achieve a maximum efficiency at each desired output signal power level, without restricting the input signal power fed to the power amplifiers to a constant level, wherein for each desired output signal power level, the digital signal component separator assigns an amplitude and phases of input signals that result in a maximum instantaneous power efficiency at the amplified output signal combined with an unmatched/non-isolating combiner (e.g. Chireix combiner).

Claims

1. An amplifier system comprising

a digital signal component separator configured to split an amplitude and phase modulated signal into a first phase modulated signal and a second phase modulated signal,

a non-isolating combiner configured to perform a signal summation of the first phase modulated signal and the second phase modulated signal,

a first power amplifier configured to perform amplification of the first phase modulated signal before the signal summation, and

a second power amplifier configured to perform amplification of the second phase modulated signal before the signal summation,

wherein the amplifier system is configured to apply a signal component separator algorithm such that the first phase modulated signal and the second phase modulated signal are allowed to take on several discrete and/or continuous amplitude levels in order to achieve a maximum efficiency at each desired output signal power level, without restricting the input signal power fed to the power amplifiers to a constant level, wherein for each desired output signal power level, the digital signal component separator assigns an amplitude and phases of input signals that result in a maximum instantaneous power efficiency of the amplifier system.

2. A system according to claim 1, characterized in that the non-isolating combiner comprises a Chireix combiner designed in accordance with the input signal'"'"'s probability distribution.

3. A system according to claim 1, characterized in that the non-isolating combiner includes harmonic terminations.

4. A system according to claim 1, characterized in that the system is configured to apply the signal component separator algorithm based on a look-up table.

5. A system according to claim 1, characterized in that it comprises a digital predistorter for digitally predistorting a signal in order to optimize linearity and intermodulation products.

6. A system according to claim 1, characterized in that it comprises a linear amplification using nonlinear components LINC outphasing system.

12. A transmitter comprising

an antenna for transmitting a radio frequency RF signal, and

an amplifier system according to claim 1.

13. A base station comprising a transmitter according to claim 12.

14. A mobile unit comprising a transmitter according to claim 12.

15. Use of an amplifier system according to claim 1 for amplifying an input signal.

16. Use according to claim 15, wherein the input signal is a base band radio frequency RF signal.

7. A method for operating an amplifier system comprising

a digital signal component separator configured to split an amplitude and phase modulated signal into a first phase modulated signal and a second phase modulated signal,

a non-isolating combiner configured to perform a signal summation of the first phase modulated signal and the second phase modulated signal,

a first power amplifier configured to perform amplification of the first phase modulated signal before the signal summation, and

a second power amplifier configured to perform amplification of the second phase modulated signal before the signal summation,

wherein the method comprises applying a signal component separator algorithm such that the first phase modulated signal and the second phase modulated signal are allowed to take on several discrete and/or continuous amplitude levels in order to achieve a maximum efficiency at each desired output signal power level, without restricting the input signal power fed to the power amplifiers to a constant level, wherein for each desired output signal power level, the digital signal component separator assigns an amplitude and phases of input signals that result in a maximum instantaneous power efficiency of the amplifier system.

8. A method according to claim 7, characterized in that the non-isolating combiner comprises a Chireix combiner designed in accordance with the input signal'"'"'s probability distribution.

9. A method according to claim 7, characterized by applying the signal component separator algorithm based on a look-up table.

10. A method according to claim 7, characterized in that the system comprises a digital predistorter for digitally predistorting a signal in order to optimize linearity and intermodulation products.

11. A method according to claim 7, characterized in that the amplifier system comprises a linear amplification using nonlinear components LINC outphasing system.

17. A circuit element for an amplifier system comprising

a digital signal component separator configured to split an amplitude and phase modulated signal into a first phase modulated signal and a second phase modulated signal,

a non-isolating combiner configured to perform a signal summation of the first phase modulated signal and the second phase modulated signal,

a first power amplifier configured to perform amplification of the first phase modulated signal before the signal summation, and

a second power amplifier configured to perform amplification of the second phase modulated signal before the signal summation,

wherein the circuit element is configured to apply a signal component separator algorithm such that the first phase modulated signal and the second phase modulated signal are allowed to take on several discrete and/or continuous amplitude levels in order to achieve a maximum efficiency at each desired output signal power level, without restricting the input signal power fed to the power amplifiers to a constant level, wherein for each desired output signal power level, the digital signal component separator assigns an amplitude and phases of input signals that result in a maximum instantaneous power efficiency of the amplifier system.