Doherty amplifier with efficiency optimization

• US 9,444,420 B2
• Filed: 06/29/2012
• Issued: 09/13/2016
• Est. Priority Date: 06/30/2011
• Status: Active Grant

• Current Assignee: Rohde & Schwarz GmbH & Company KG
• Original Assignee: Rohde & Schwarz GmbH & Company KG
• Inventors: Dalisda, Uwe, Mhlbacher, Peter
• Primary Examiner(s): NGUYEN, HIEU P
• Application Number:
  US14/116,994
• Publication Number:
  US 20140085000A1
• Time in Patent Office: 1,537 Days
• Field of Search: 330/124.R, 330/295, 330/286, 330/53, 330/84
• US Class Current: 1/1
• 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 1/0288 using a main and one or several auxiliary peaking amplifiers whereby the load is connected to the main amplifier using an impedance inverter, e.g. Doherty amplifiers
• 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 comprises a main-amplifier circuit, an auxiliary-amplifier circuit and a signal-generating device. Output terminals of the main-amplifier circuit and of the auxiliary-amplifier circuit are connected according to the Doherty principle. The signal-generating device is configured to generate directly a main-amplifier signal as an input signal of the main-amplifier circuit and an auxiliary-amplifier signal as an input signal of the auxiliary-amplifier circuit.

Claims

1. An amplifier comprising:

a main-amplifier circuit;

an auxiliary-amplifier circuit, whereas the output terminals of the main-amplifier circuit and the auxiliary-amplifier circuit are connected according to the Doherty principle;

a signal-generating device configured to generate directly a main-amplifier signal as an input signal of the main-amplifier circuit and an auxiliary-amplifier signal as an input signal of the auxiliary-amplifier circuit; and

a control device configured to control the signal-generating device, wherein the control device is configured to determine a threshold value on the basis of the signal to be amplified in order to determine the main-amplifier signal and the auxiliary-amplifier signal, and wherein the control device is configured to adjust the threshold value in an efficiency-optimizing manner on the basis of a statistical amplitude distribution of the signal to be amplified.

2. The amplifier according to claim 1,

wherein the main-amplifier signal corresponds to a signal to be amplified, and wherein the auxiliary-amplifier signal corresponds to the signal peaks of the signal to be amplified.

3. The amplifier according to claim 1,

wherein the main-amplifier signal and the auxiliary-amplifier signal are phase shifted.

4. The amplifier according to claim 1,

wherein the signal-generating device is configured to generate the main-amplifier signal and the auxiliary-amplifier signal by modulation and/or from digital data to be transmitted.

5. The amplifier according to claim 1,

wherein the signal-generating device includes a modulator or control transmitter.

6. The amplifier according to claim 1,

wherein the amplifier further contains a bias-current generating device, and wherein the bias-current generating device is configured to generate bias-currents of the main-amplifier circuit and the auxiliary-amplifier circuit.

7. The amplifier according to claim 6,

wherein the control device is configured to control the bias-current generating device.

8. The amplifier according to claim 6,

wherein the control device is configured to adjust the bias-currents of the main-amplifier circuit and the auxiliary-amplifier circuit in an efficiency-optimizing manner on the basis of statistical advance information relating to the signal to be amplified.

9. The amplifier according to claim 1,

wherein the control device is configured to maximize a mean efficiency over a totality of transmission symbols to be transmitted.

10. The amplifier according to claim 3, wherein the main-amplifier signal and the auxiliary-amplifier signal are phase shifted by 90°

.