Cascode amplifier circuit

A cascode amplifier circuit comprising:

• a cascode connection circuit comprising:
• a first transistor to which a radio frequency signal is input;
• at least one second transistor that is cascode-connected to the first transistor;
• a bias circuit configured to supply a bias to the at least one second transistor;
• and
• a power supply wiring line through which a variable power supply voltage is applied to the cascode connection circuit,
• wherein the bias circuit comprises:
• a resistor voltage divider circuit that is connected between the power supply wiring line and a reference potential, that has at least one voltage dividing point corresponding to the at least one second transistor, and that is configured to supply the bias to the corresponding second transistor based on a voltage at the at least one voltage dividing point;
• a bias voltage source configured to generate a reference voltage that serves as a base for the bias supplied to the at least one second transistor;
• and
• at least one first diode connected between an output node of the bias voltage source and the at least one voltage dividing point, the at least one first diode being connected in a direction serving as a forward direction from the output node of the bias voltage source to the at least one voltage dividing point.