Radio frequency amplifier circuit

1. A radio frequency amplifier circuit comprising:

a plurality of first transistors, each of which includes an input terminal, an output terminal, and a ground terminal, and amplifies a radio frequency signal;

an output-side harmonic processing circuit provided for each of the first transistors to be connected to the output terminal of the first transistor, the output-side harmonic processing circuit processing even harmonics or odd harmonics both included in the amplified radio frequency signal, thereby operating in a class-F mode or an inverse class-F mode; and

an output-side resistor connected to the output terminal of each of the first transistors,

wherein the input terminal of each of the first transistors is connected to an input terminal of the radio frequency amplifier circuit via an input matching element, and

the output terminal of each of the first transistors is connected to the output terminal of the other one of the first transistors via the output-side resistor, and is further connected to an output terminal of the radio frequency amplifier circuit via an output matching element.

2. The radio frequency amplifier circuit according to claim 1 ,

wherein an impedance of each of output-side resistors which include the output-side resistor in a frequency band of the radio frequency signal is higher than a real part of an output impedance of each of the first transistors which are connected in parallel to each other not via the output-side resistor.

3. The radio frequency amplifier circuit according to claim 1 ,

wherein each of output-side harmonic processing circuits which include the output-side harmonic processing circuit includes:

a first inductor which has a first end connected to the output terminal of the first transistor: and

a first capacitor which has a first end connected to a second end of the first inductor, and a second end grounded, and

the output-side harmonic processing circuit is a series resonant circuit which resonates at a frequency twice as high as a fundamental frequency of each of the first transistors.

4. The radio frequency amplifier circuit according to claim 1 , further comprising

an output-side fundamental matching circuit connected to the output terminal of the first transistor and the output-side harmonic processing circuit, the output-side fundamental matching circuit selectively passing a fundamental included in the amplified radio frequency signal,

wherein the output-side fundamental matching circuit includes:

second inductors, each of which serves as the output matching element, and has a first end connected to the output terminal of the first transistor and a second end connected to the second end of another second inductor; and

a second capacitor which has a first end connected to every second end of the second inductors, and a second end grounded.

5. The radio frequency amplifier circuit according to claim 1 ,

wherein the first transistors and output-side resistors including the output-side resistor are formed on a single chip, and

output-side harmonic processing circuits including the output-side harmonic processing circuit are mounted inside a package in which the chip is mounted.

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

an input-side harmonic processing circuit which is provided for each of the first transistors to be connected to the input terminal of the first transistor, the input-side harmonic processing circuit processing the even harmonics or the odd harmonics both included in the amplified radio frequency signal, thereby operating in the class-F mode or the inverse class-F mode; and

an input-side resistor connected to the input terminal of each of the first transistors,

wherein the input terminal of each of the first transistors is connected to the input terminal of the other one of the first transistors via the input-side resistor.

7. The radio frequency amplifier circuit according to claim 6 ,

wherein an impedance of each of input-side resistors which include the input-side resistor in a frequency band of the radio frequency signal is higher than an input impedance of each of the first transistors which are connected in parallel to each other.

8. The radio frequency amplifier circuit according to claim 6 ,

wherein each of input-side harmonic processing circuits which include the input-side harmonic processing circuit includes:

a third inductor which has a first end connected to the input terminal of the first transistor; and

a third capacitor which has a first end connected to a second end of the third inductor, and a second end grounded, and

the input-side harmonic processing circuit is a series resonant circuit which resonates at a frequency twice as high as a fundamental frequency of each of the first transistors.

9. The radio frequency amplifier circuit according to claim 6 , further comprising

an input-side fundamental matching circuit connected to the input terminal of the first transistor and the input-side harmonic processing circuit, the input-side fundamental matching circuit selectively passing a fundamental included in the amplified radio frequency signal,

wherein the input-side fundamental matching circuit includes:

fourth inductors, each of which serves as the input matching element, and has a first end connected to the input terminal of the first transistor, and a second end connected to the second end of another fourth inductor; and

a fourth capacitor which has a first end connected to every second end of the fourth inductors, and a second end grounded.

10. The radio frequency amplifier circuit according to claim 6 ,

wherein input-side resistors including the input-side resistor, the first transistors, and output-side resistors including the output-side resistor are formed on a single chip, and

input-side harmonic processing circuits including the input-side harmonic processing circuit and output-side harmonic processing circuits including the output-side harmonic processing circuit are mounted inside a package in which the chip is mounted.

11. The radio frequency amplifier circuit according to claim 1 , further comprising:

a plurality of second transistors, each of which includes an input terminal, an output terminal, and a ground terminal, and amplifies the harmonic signal,

wherein the input terminal of each of the second transistors is connected to the input terminal of the radio frequency amplifier circuit via the input matching element, and

the output terminal of each of the second transistors is connected to the output terminal of the radio frequency amplifier circuit via the output matching element, and is further short -circuited to the output terminal of an adjacent one of the first transistors.

12. The radio frequency amplifier circuit according to claim 11 ,

wherein the second transistors, the first transistors, and output-side resistors including the output-side resistor are formed on a single chip, and

output-side harmonic processing circuits including the output-side harmonic processing circuit are mounted in a package in which a chip is mounted.