Distributed amplifier and integrated circuit

A distributed amplifier for amplifying a signal applied to an input terminal and including components in a predetermined frequency range to deliver the amplified signal from an output terminal, said distributed amplifier comprising:

• a plurality of transistors which operate as amplification elements;
• an input side coupling circuit including a plurality of distributed constant lines connected in series, one terminal of which is the input terminal, and another terminal of which is a bias input terminal, wherein each of the connections of said distributed constant lines with each other is connected to an input of each of said plurality of transistors;
• an output side coupling circuit including a plurality of distributed constant lines connected in series, one terminal of which is the output terminal, and another terminal of which is a bias input terminal, wherein each of the connections of said distributed constant lines with each other is connected to an output of each of said plurality of transistors;
• and
• a termination circuit contained in at least one of said input side coupling circuit and said output side coupling circuit, including a first resistor connected between the bias input terminal and a voltage source, and a second resistor connected between the bias input terminal and a ground potential,
• wherein said first resistor has a resistance value equal to or smaller than a resistance value of said second resistor,
• said termination circuit further includes an inductor connected between said first resistor and said voltage source, a first capacitor connected between a connection point of said first resistor and said inductor and the ground potential point, and a second capacitor connected between a connection point of said inductor and said voltage source and the ground potential point, and
• the resistance value of said first resistor, the resistance value of said second resistor, the inductance of said inductor, the capacitance of said first capacitor, and the capacitance of said second capacitor are selected such that the impedance of an equivalent circuit, in which said inductor and said second capacitor are connected in series, the series circuit and said first capacitor are connected in parallel, the parallel circuit and said first resistor are connected in series, and said second resistor is connected in parallel with the circuit, has a value within a predetermined range in the predetermined frequency range.