Power amplification by using different fixed power supply signals for the amplifier

• US 20040008081A1
• Filed: 06/23/2003
• Published: 01/15/2004
• Est. Priority Date: 07/09/2002
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Friedel, Bernd, Ritter, Kai-Uwe
• Granted Patent: US 7,091,772 B2
• Time in Patent Office: Days
• US Class Current: 330/10
• CPC Class Codes: H03F 1/0227 using supply converters
• CPC Class Codes: H03F 1/025 by using a signal derived from the input signal
• CPC Class Codes: H03F 1/0261 with control of the polarisation voltage or current, e.g. gliding Class A
• CPC Class Codes: H03F 2200/511 Many discrete supply voltages or currents or voltage levels can be chosen by a control signal in an IC-block amplifier circuit

Abstract

The present invention proposes a power amplification under variable envelope excitation, wherein an original input signal at least is converted into a phase modulated signal part, at least the phase modulated signal part is fed to an input port of an amplifier unit, the input signal is amplified by dynamically selecting a fixed power supply (PSU 1, PSU 2, PSU 3) for the amplifier unit, and wherein the amplitude content of the original input signal is reconstructed by changing dependent on the respective provided power supply a further controllable input of the amplifier unit, in particular the input power level (P_in) and/or the biasing voltage (U_g) and/or biasing current at the control input of the amplifier unit, during said step of amplifying.

Claims

1. A method of performing power amplification under variable envelope excitation, comprising the steps of:

converting an original input signal at least into a phase modulated signal part;

feeding at least the phase modulated signal part to an input port of an amplifier unit; and

amplifying the input signal by dynamically selecting a fixed power supply for the amplifier unit, wherein the amplitude content of the original input signal is reconstructed by changing dependent on the respective provided power supply a further controllable input of the amplifier unit, in particular the input power level and/or the biasing voltage and/or biasing current at the control input of the amplifier unit, during said step of amplifying.

2. The method of claim 1, further characterized in that the dynamical selection of a fixed power supply is performed by switching between at least two different fixed supply currents or supply voltages, in particular by taken into account the difference in providing gain.

3. The method of claim 1, further comprising the step of operating the amplifier unit with the phase modulated signal part in a non-overdriven condition.

4. The method of claim 1, further comprising the step of compensating non-linearity by pre-distorting the power supply for the amplifier unit and/or by pre-distorting the amplifier unit biasing voltage and/or biasing current at the control input.

5. The method of claim 1, further comprising the step of lowpass filtering of a control signal for providing the changeable amplifier unit biasing voltage and/or biasing current at the control input with a cut-off frequency close to the modulation bandwidth of the original input signal.

6. The method of claim 1, further comprising the step of converting the original input signal into an amplitude modulated signal part, according to which the input power level is changed.

7. A power amplifier comprising

at least a final amplifier unit;

means for feeding at least the phase modulated signal part of an original input signal to the input port of the amplifier unit;

at least two selectable power supply units with different fixed output powers connected to the supply port of the amplifier unit;

means for dynamically selecting a total supply power by selecting the respective power supply unit or units; and

means for controlling dependent on the respective selected supply power a further amplifier unit input, in particular the input power level and/or the biasing voltage and/or biasing current at the control input of the amplifier unit.

8. The power amplifier of claim 7, wherein each of the power supply units comprises a DC/DC converter and/or is connected to the supply port in parallel and/or is selected by a common digital signal processor.

9. The power amplifier of claim 7, wherein a linear regulator is used to control the amplifiers biasing voltage and/or current at the control input and/or wherein a control path with a lowpass filter for controlling the amplifier unit input biasing voltage and/or biasing current is comprised.

10. The power amplifier of claim 7, wherein the means for controlling the amplifier unit input power level comprises a digital signal processor and/or the means for controlling the amplifier unit input biasing voltage and/or biasing current comprises a digital signal processor and a D/A converter.