Amplifier

A multi-stage amplifier comprising:

• a plurality of amplifiers that is cascade-connected, wherein each of the plurality of amplifiers includes a plurality of amplifier circuits connected in series between a ground and a power supply, wherein each of the plurality of amplifier circuits includes:
• a transistor;
• and
• a first capacitance, one end of which is connected to a drain of the transistor, a first amplifier circuit connected closest to the power supply among the plurality of amplifier circuits includes a load connected between the drain of the transistor and the power supply, each of the plurality of amplifier circuits except for the first amplifier circuit includes a load connected between the drain of the transistor of an own amplifier circuit and a source of the transistor of an amplifier circuit adjacent to the own amplifier circuit, each of the plurality of amplifier circuits except for an amplifier circuit connected farthest from the power supply includes a second capacitance connected between the source of the transistor and the ground, and the second capacitance has a capacitance value larger than a capacitance value of the first capacitance,
• when the transistor is used as the first transistor, each of the plurality of amplifier circuits includes:
• a second transistor, of which a source is shared with the first transistor, and a third capacitance, one end of which is connected to a drain of the second transistor, the first amplifier circuit includes a load connected between the drain of the second transistor and the power supply, and each of the plurality of amplifier circuits except for the first amplifier circuit includes a load connected between the drain of the second transistor of an own amplifier circuit and the source of the second transistor of an amplifier circuit adjacent to the own amplifier circuit.