LINC power transmitter

• US 20040185805A1
• Filed: 01/30/2004
• Published: 09/23/2004
• Est. Priority Date: 02/21/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Postech Foundation
• Inventors: Kim, Seung Woo, Yi, Jae Hyok, Woo, Young Yun, Yang, Youngoo, Kim, Bumman
• Granted Patent: US 7,200,369 B2
• Time in Patent Office: Days
• US Class Current: 455/114.3
• CPC Class Codes: H03F 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 1/0294 using vector summing of two or more constant amplitude phase-modulated signals
• CPC Class Codes: H03F 2200/15 the supply or bias voltage or current at the drain side of a FET being continuously controlled by a controlling signal
• CPC Class Codes: H03F 2200/18 the bias of the gate of a FET being controlled by a control signal
• CPC Class Codes: H03F 2200/336 A I/Q, i.e. phase quadrature, modulator or demodulator being used in an amplifying circuit
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 1/0483 Transmitters with multiple parallel paths

Abstract

A linear amplification with nonlinear components (LINC) power transmitter is provided. The LINC power transmitter includes a digital signal processing unit which controls the LINC power transmitter; a frequency modulation unit which modulates or converts a digital signal output from the digital signal processing unit into a radio-frequency (RF) signal; a signal amplification unit which amplifies the RF signal output from the frequency modulation unit using a gain amplifier and a power amplification module; and a direct current/direct current (DC/DC) conversion unit which controls bias of the power amplification module. Here, the DC/DC conversion unit controls a base bias and/or a collect bias of the power amplification module, and the power amplification module operates in saturation.

Claims

1. A linear amplification with nonlinear components (LINC) power transmitter, comprising:

a digital signal processing unit which controls the LINC power transmitter;

a frequency modulation unit which modulates or converts a digital signal output from the digital signal processing unit into a radio-frequency (RF) signal;

a signal amplification unit which amplifies the RF signal output from the frequency modulation unit using a gain amplifier and a power amplification module; and

a direct current/direct current (DC/DC) conversion unit which controls bias of the power amplification module,

wherein the DC/DC conversion unit controls a base bias and/or a collect bias of the power amplification module, and the power amplification module operates in saturation.

2. The LINC power transmitter of claim 1, wherein the digital signal processing unit comprises:

a signal component separator which separates a predetermined signal into its components;

a local oscillator controller which controls a local oscillator of the frequency modulation unit; and

a bias/level controller which controls the base bias signal and the collect bias signal to be provided to the signal amplification unit.

3. The LINC power transmitter of claim 1 or 2, wherein the frequency modulation unit comprises:

a digital/analog (D/A) converter which receives a digital signal output from the signal component separator and converts the received digital signal into an analog signal;

a low pass filter which only passes a low frequency signal among analog signals output from the D/A converter;

a quadrature modulator which quadrature-modulates a signal output from the low pass filter; and

a local oscillator which provides an oscillation signal to operate the quadrature modulator.

4. The LINC power transmitter of claim 3, wherein the signal amplification unit comprises:

a gain amplifier which amplifies gain of a signal output from the quadrature modulator;

a power amplification module which amplifies a signal output from the gain amplifier using the base bias and collect bias of the DC/DC conversion unit; and

a signal combiner which combines output signals from the power amplification module.

5. The LINC power transmitter of claim 4, wherein the power amplification module comprises a power amplifier corresponding to the gain amplifier and is a commonly-used amplifier or a differential amplifier.

6. The LINC power transmitter of claim 4, wherein the DC/DC conversion unit comprises a DC/DC converter which is controlled by the bias/level controller of the digital signal processing unit, provides the base bias and the collect bias to the power amplification module and adjusts an output level of the power amplification module by bias control.

7. The LINC power transmitter of claim 1, wherein the power amplification module comprises a virtual ground for removing a predetermined error signal.

8. The LINC power transmitter of claim 7, wherein the power amplification module further comprises an impedance matching load which is connected to the virtual ground and removes the error signal.

9. The LINC power transmitter of claim 1 being able to be applied to a software defined radio (SDR) power transmitter which changes communication modes using software.