High frequency amplifier circuit

A high frequency amplifier circuit comprising:

• a first transistor that has a first terminal, a second terminal and a control terminal, the first terminal being grounded;
• a second transistor that has a first terminal, a second terminal and a control terminal, the control terminal of the second transistor being coupled to the second terminal of the first transistor, the first terminal of the second transistor being coupled to only the second terminal of the first transistor with respect to high frequency wave, the second terminal of the second transistor being coupled to a direct-current power supply;
• and
• a first resistor of which first terminal is coupled to a node between the second terminal of the first transistor and the control terminal of the second transistor, and of which second terminal is coupled to the first terminal of the second transistor,
• wherein a phase difference between a voltage of the control terminal of the second transistor and a voltage of the first terminal of the second transistor is in a range of 90 degrees or more and 270 degrees or less.

A high frequency amplifier circuit comprising:

• a first transistor that has a first terminal, a second terminal and a control terminal, the first terminal being grounded;
• a second transistor that has a first terminal, a second terminal and a control terminal, the control terminal of the second transistor being coupled to the second terminal of the first transistor, the first terminal of the second transistor being coupled to only the second terminal of the first transistor with respect to high frequency wave, the second terminal of the second transistor being coupled to a direct-current power supply;
• and
• a first resistor of which first terminal is coupled to a node between the second terminal of the first transistor and the control terminal of the second transistor, and of which second terminal is coupled to the first terminal of the second transistor,
• wherein a second resistor and a first capacitor are coupled between the first terminal of the first transistor and the ground in parallel.

A high frequency amplifier circuit comprising:

• a first transistor that has a first terminal, a second terminal and a control terminal, the first terminal being grounded;
• a second transistor that has a first terminal, a second terminal and a control terminal, the control terminal of the second transistor being coupled to the second terminal of the first transistor, the first terminal of the second transistor being coupled to only the second terminal of the first transistor with respect to high frequency wave, the second terminal of the second transistor being coupled to a direct-current power supply;
• a first resistor of which first terminal is coupled to a node between the second terminal of the first transistor and the control terminal of the second transistor, and of which second terminal is coupled to the first terminal of the second transistor;
• and
• a first distributed constant line of which first terminal is coupled to the first resistor, and of which second terminal is coupled to the node.