POWER AMPLIFIER CIRCUIT

• US 20180152143A1
• Filed: 11/22/2017
• Published: 05/31/2018
• Est. Priority Date: 11/25/2016
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Tanaka, Satoshi, Hase, Masatoshi, Honda, Yuri, Watanabe, Kazuo, Soga, Takashi
• Granted Patent: US 10,135,395 B2
• Time in Patent Office: Days
• CPC Class Codes: H03F 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 1/0261 with control of the polarisation voltage or current, e.g. gliding Class A
• CPC Class Codes: H03F 1/22 by use of cascode coupling, i.e. earthed cathode or emitter stage followed by earthed grid or base stage respectively
• CPC Class Codes: H03F 1/56 Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/222 A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier
• 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 2200/411 the output amplifying stage of an amplifier comprising two power stages
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2200/516 Some amplifier stages of an amplifier use supply voltages of different value
• CPC Class Codes: H03F 3/195 in integrated circuits
• CPC Class Codes: H03F 3/213 in integrated circuits

Abstract

A power amplifier circuit includes a first transistor, a second transistor, a first bias circuit supplying a first bias current or voltage, a second bias circuit supplying a second bias current or voltage, a first inductor, and a first capacitor. A power supply voltage is supplied to a collector of the first transistor, and an emitter thereof is grounded. A radio frequency signal and the first bias current or voltage are supplied to a base of the first transistor. The power supply voltage is supplied to a collector of the second transistor, and an emitter thereof is connected to the collector of the first transistor via the first capacitor and is grounded via the first inductor. The second bias current or voltage is supplied to a base of the second transistor. An amplified radio frequency signal is output from the collector of the second transistor.

Claims

1. A power amplifier circuit comprising:

a first transistor;

a second transistor;

a first bias circuit that supplies a first bias current or a first bias voltage;

a second bias circuit that supplies a second bias current or a second bias voltage;

a first inductor; and

a first capacitor, wherein

a power supply voltage is supplied to a collector of the first transistor,

an emitter of the first transistor is grounded,

a radio frequency signal and the first bias current or the first bias voltage are supplied to a base of the first transistor,

the power supply voltage is supplied to a collector of the second transistor,

an emitter of the second transistor is connected to the collector of the first transistor via the first capacitor, and is grounded via the first inductor,

the second bias current or the second bias voltage is supplied to a base of the second transistor, and

an amplified signal generated by amplifying the radio frequency signal is output from the collector of the second transistor.

2. The power amplifier circuit according to claim 1, further comprising:

a voltage adjusting circuit that adjusts a base voltage of the second transistor.

3. The power amplifier circuit according to claim 2, wherein the voltage adjusting circuit includes a second capacitor that is connected at one end to the base of the second transistor and is grounded at the other end.

4. The power amplifier circuit according to claim 2, wherein the voltage adjusting circuit includes a second inductor between the second bias circuit and the base of the second transistor.

5. The power amplifier circuit according to claim 3, wherein the voltage adjusting circuit includes a second inductor between the second bias circuit and the base of the second transistor.

6. The power amplifier circuit according to claim 1, further comprising:

a third transistor;

a third bias circuit that supplies a third bias current or a third bias voltage;

a third inductor; and

a third capacitor, wherein

the power supply voltage is supplied to a collector of the third transistor,

an emitter of the third transistor is connected to the collector of the second transistor via the third capacitor, and is grounded via the third inductor,

the third bias current or the third bias voltage is supplied to a base of the third transistor, and

an amplified signal generated by amplifying the radio frequency signal is output from the collector of the third transistor.

7. The power amplifier circuit according to claim 2, further comprising:

a third transistor;

a third bias circuit that supplies a third bias current or a third bias voltage;

a third inductor; and

a third capacitor, wherein

the power supply voltage is supplied to a collector of the third transistor,

an emitter of the third transistor is connected to the collector of the second transistor via the third capacitor, and is grounded via the third inductor,

the third bias current or the third bias voltage is supplied to a base of the third transistor, and

an amplified signal generated by amplifying the radio frequency signal is output from the collector of the third transistor.

8. The power amplifier circuit according to claim 3, further comprising:

a third transistor;

a third bias circuit that supplies a third bias current or a third bias voltage;

a third inductor; and

a third capacitor, wherein

the power supply voltage is supplied to a collector of the third transistor,

an emitter of the third transistor is connected to the collector of the second transistor via the third capacitor, and is grounded via the third inductor,

the third bias current or the third bias voltage is supplied to a base of the third transistor, and

an amplified signal generated by amplifying the radio frequency signal is output from the collector of the third transistor.

9. The power amplifier circuit according to claim 4, further comprising:

a third transistor;

a third bias circuit that supplies a third bias current or a third bias voltage;

a third inductor; and

a third capacitor, wherein

the power supply voltage is supplied to a collector of the third transistor,

an emitter of the third transistor is connected to the collector of the second transistor via the third capacitor, and is grounded via the third inductor,

the third bias current or the third bias voltage is supplied to a base of the third transistor, and

an amplified signal generated by amplifying the radio frequency signal is output from the collector of the third transistor.

10. The power amplifier circuit according to claim 1, wherein the first capacitor is mounted on an integrated circuit on which the first and second transistors are mounted.

11. The power amplifier circuit according to claim 2, wherein the first capacitor is mounted on an integrated circuit on which the first and second transistors are mounted.

12. The power amplifier circuit according to claim 3, wherein the first capacitor is mounted on an integrated circuit on which the first and second transistors are mounted.

13. The power amplifier circuit according to claim 4, wherein the first capacitor is mounted on an integrated circuit on which the first and second transistors are mounted.

14. The power amplifier circuit according to claim 6, wherein the first capacitor is mounted on an integrated circuit on which the first and second transistors are mounted.

15. The power amplifier circuit according to claim 1, wherein the first inductor is mounted on a substrate different from an integrated circuit on which the first and second transistors are mounted.

16. The power amplifier circuit according to claim 2, wherein the first inductor is mounted on a substrate different from an integrated circuit on which the first and second transistors are mounted.

17. The power amplifier circuit according to claim 3, wherein the first inductor is mounted on a substrate different from an integrated circuit on which the first and second transistors are mounted.

18. The power amplifier circuit according to claim 4, wherein the first inductor is mounted on a substrate different from an integrated circuit on which the first and second transistors are mounted.

19. The power amplifier circuit according to claim 6, wherein the first inductor is mounted on a substrate different from an integrated circuit on which the first and second transistors are mounted.

20. The power amplifier circuit according to claim 10, wherein the first inductor is mounted on a substrate different from an integrated circuit on which the first and second transistors are mounted.