Amplifier

• US 7,710,202 B2
• Filed: 09/29/2008
• Issued: 05/04/2010
• Est. Priority Date: 09/17/2003
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Shiikuma, Kazumi
• Primary Examiner(s): Nguyen; Patricia
• Application Number:
  US12/285,087
• Publication Number:
  US 20090045878A1
• Time in Patent Office: 582 Days
• Field of Search: 330/295, 330/124.R, 330/286
• US Class Current: 330/295
• 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 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers

Abstract

An amplifier includes a carrier amplifier which performs signal amplification at all times, a peak amplifier which operates only at a time when the high electric power is outputted, a combiner which combines the output from the carrier amplifier and the peak amplifier, and a distributor which distributes an input signal to the carrier amplifier and the peak amplifier. The carrier amplifier and the peak amplifier are included in a single package transistor.

Claims

1. A Doherty amplifier, comprising:

a distributor which distributes input signals to two amplifiers;

one or a plurality of linear amplifiers into which one signal from the distributor is input;

one or a plurality of nonlinear amplifiers into which the other signal from the distributor is input; and

a combiner that combines output signals from the linear amplifier and the nonlinear amplifier,

wherein the Doherty amplifier comprises a plurality of transistors built into one package for a push-pull amplifier or a balance amplifier, and

wherein each of a predetermined number of the transistors operates for the linear amplifier, and each of the other transistors operates for the nonlinear amplifier.

2. The Doherty amplifier according to claim 1, wherein the linear amplifier comprises a carrier amplifier, and the nonlinear amplifier comprises a peak amplifier.

3. The Doherty amplifier according to claim 1, wherein the plurality of transistors comprise two transistors included in the one package, wherein one of the transistors operates for the linear amplifier, and the other transistor operates for the nonlinear amplifier.

4. The Doherty amplifier according to claim 1, wherein the package is directly connected to at least a gate electrode and a drain electrode.

5. The Doherty amplifier according to claim 1, wherein the distributor sets a phase relation between the linear amplifier and the nonlinear amplifier so that the signals are combined in the same phase at a signal combining point of the combiner.

6. The Doherty amplifier according to claim 1, wherein the distributor comprises a ¼

wavelength transmission line or a 90°

hybrid circuit.

7. The Doherty amplifier according to claim 1, wherein the combiner comprises any of a transformer, an impedance converter, and a ¼

wavelength transmission line.

8. The Doherty amplifier according claim 1, wherein the linear amplifier is biased in a first class while the nonlinear amplifier is biased in a second class different from the first class.

9. The Doherty amplifier according to claim 1, wherein the linear amplifier amplifies a signal at all times, and the nonlinear amplifier amplifies the signal only at a time of the outputting of a high electric power.

10. The Doherty amplifier according to claim 1, wherein the package comprises a gate electrode and a drain electrode.