High frequency power amplifier

• US 20020063603A1
• Filed: 06/18/2001
• Published: 05/30/2002
• Est. Priority Date: 11/29/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Ohta, Akira, Gotou, Seiki
• Granted Patent: US 6,759,908 B2
• Time in Patent Office: Days
• US Class Current: 330/302
• CPC Class Codes: H03F 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 3/604 using FET's

Abstract

A high frequency power amplifier that can improve an efficiency of an operation of a transistor without limiting any input-side higher harmonic load of an impedance matching circuit to a short-circuit load, and can increase a quantity of reflection of higher harmonics. By adjusting line lengths L1 to L5 and line widths W1 to W5 of the signal lines 1 to 5, a 2nd higher harmonic can be adjusted to be an open load (a reflected phase angle of Γin: 0-90°, the quantity of reflection: 0.6-1.0), and a 3rd higher harmonic is adjusted to be a short-circuit load (the reflected phase angle of Γin:110-270°, the quantity of reflection: 0.6-1.0). By this optimization of an input-side higher harmonic load of the impedance matching circuit, an efficiency of transistor operation can be improved. By disposing a higher harmonic processing circuit 12 of higher orders closer to a transistor 1, there is provided a high frequency power amplifier with a shortened line length between the higher harmonic processing circuit 12 and the transistor 1, and increased quantity of reflection of higher harmonics.

Claims

1. A high frequency power amplifier, comprising:

a transistor for amplifying signals; and

an input-side impedance matching circuit connected to an input side of said transistor,

wherein said input-side impedance matching circuit makes impedance substantially open load with respect to even number order higher harmonics of a fundamental wave of a high frequency signal.

2. The high frequency power amplifier according to claim 1, wherein a phase angle of reflection of a second higher harmonic is 0 to 90 degrees, and a quantity of reflection is 0.6 to 1.0, with respect to a reflection coefficient when said input-side impedance matching circuit is viewed from a direction of an input end of said transistor.

3. The high frequency power amplifier according to claim 2, wherein said input-side impedance matching circuit comprises a third higher harmonic reflecting circuit, a second higher harmonic processing circuit, and a fundamental wave matching circuit, disposed sequentially from a side of a signal input terminal.

4. The high frequency power amplifier according to claim 1, wherein said input-side impedance matching circuit comprises a third higher harmonic reflecting circuit, a second higher harmonic processing circuit, and a fundamental wave matching circuit, disposed sequentially from a side of a signal input terminal.

5. A high frequency power amplifier, comprising:

a transistor for amplifying signals; and

an input-side impedance matching circuit connected to an input side of said transistor,

wherein said input-side impedance matching circuit makes impedance substantially short-circuit load with respect to odd number order higher harmonics of a fundamental wave of a high frequency signal.

6. The high frequency power amplifier according to claim 5, wherein a phase angle of reflection of a third higher harmonic is 110 to 270 degrees, and a quantity of reflection is 0.6 to 1.0, with respect to a reflection coefficient when said input-side impedance matching circuit is viewed from a direction of an input end of said transistor.

7. The high frequency power amplifier according to claim 6, wherein said input-side impedance matching circuit comprises a third higher harmonic reflecting circuit, a second higher harmonic processing circuit, and a fundamental wave matching circuit, disposed sequentially from a side of a signal input terminal.

8. The high frequency power amplifier according to claim 5, wherein said input-side impedance matching circuit comprises a third higher harmonic reflecting circuit, a second higher harmonic processing circuit, and a fundamental wave matching circuit, disposed sequentially from a side of a signal input terminal.

9. A high frequency power amplifier, comprising:

a front stage transistor;

a rear stage transistor; and

an inter-stage impedance matching circuit connected between said front stage transistor and said rear stage transistor for matching impedances,

wherein higher harmonics generated in said front stage transistor is inputted into said rear stage transistor, and a higher harmonic load of said rear stage transistor is adjusted by said inter-stage impedance matching circuit.