High frequency power amplifier

• US 6,700,440 B2
• Filed: 05/23/2002
• Issued: 03/02/2004
• Est. Priority Date: 05/30/2001
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Hareyama, Nobuo
• Primary Examiner(s): NGUYEN, KHANH V
• Application Number:
  US10/155,634
• Publication Number:
  US 20020186076A1
• Time in Patent Office: 649 Days
• Field of Search: 330/51, 330/127, 330/296, 330/297, 330/302
• US Class Current: 330/51
• CPC Class Codes: H03F 1/0238 using supply converters
• CPC Class Codes: H03F 1/56 Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 2200/387 A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier
• CPC Class Codes: H03F 2200/391 the output circuit of an amplifying stage comprising an LC-network
• CPC Class Codes: H03F 2200/421 Multiple switches coupled in the output circuit of an amplifier are controlled by a circuit
• CPC Class Codes: H03F 2203/21157 A filter circuit being added at the output of a power amplifier stage
• CPC Class Codes: H03F 2203/21175 An output signal of a power amplifier being on/off switched
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03G 1/0088 using discontinuously variable devices, e.g. switch-operated
• CPC Class Codes: H04B 1/0458 Arrangements for matching and coupling between power amplifier and antenna or between amplifying stages matching circuits in general H03H
• CPC Class Codes: H04B 1/0483 Transmitters with multiple parallel paths

Abstract

A high-frequency power amplifier system including a plurality of individual amplifiers connected in parallel, the amplifiers including switching-driven FET'"'"'s. A fixed drain voltage is applied to one amplifier and a variable drain voltage is applied to another amplifier through a section including a DC-DC converter that converts the voltage according to a control value of a control signal. The turning on and off of the operation of the power amplifier is controlled by a control signal. Also, the circuit constants of a matching circuit are variable. In a high output power region, the power amplifier is turned on and, in a low output power region, turned off. Thereby, the decrease of efficiency of the power amplifier, owing to the DC-DC converter, may be suppressed to a minimum. The matching of the amplifier is adjusted when the power amplifier is switched on or off so as to improve efficiency. Consequently, it becomes possible to continuously control the output of the amplifier.

Claims

1. A high-frequency power amplifier having a plurality of switching-driven transistors, said amplifier comprising:

a plurality of switching-driven transistors connected in parallel with each other;

means for applying a fixed drain voltage to a first portion of said plurality of transistors;

means for applying a variable drain voltage to a second portion of said plurality of transistors according to a control value;

means for turning on or off an operation of the first portion of said plurality of transistors having a fixed drain voltage; and

means for controlling an output of said amplifier by varying an output of said high-frequency power amplifier through controlling a drain voltage of said second portion of said plurality of transistors and by turning on the operation of the first portion of said plurality of transistors in a high output power region and, in a low output power region, turning off the operation of said plurality of transistors that have been turned on.

2. The high-frequency power amplifier according to claim 1, further comprising:

a matching circuit having a variable circuit constant connected to an output side of said plurality of transistors; and

means for optimizing said variable circuit constant of said matching circuit according to the output of said high-frequency amplifier.

3. The high-frequency power amplifier according to claim 2, wherein said means for optimizing said variable circuit constant includes means for switching said variable circuit constant in accordance with the turning on or off of the operation of said first portion of said plurality of transistors.

4. The high-frequency power amplifier according to claim 1, wherein said means for applying the variable drain voltage to said second portion of said plurality of transistors includes means for enabling continuous control of the applied drain voltage.

5. The high-frequency power amplifier according to claim 4, wherein said means for enabling continuous control of the applied drain voltage includes a DC-DC converter.

6. A high-frequency power amplifier using a plurality of switching-driven transistors, said amplifier comprising:

a plurality of switching-driven transistors connected in parallel with each other;

a first unit for applying a fixed drain voltage to a first portion of said plurality of transistors;

a second unit for applying a variable drain voltage to a second portion of said plurality of transistors according to a control value;

a switching unit for turning on or off an operation of the first portion of said plurality of transistors having a fixed drain voltage; and

a controller for controlling an output of said amplifier by varying an output of said amplifier through controlling a drain voltage of said second portion of said plurality of transistors and by turning on the operation of the first portion of said plurality of transistors in a high output power region and, in a low output power region, turning off the operation of said plurality of transistors that have been turned on.