When the signal level of a signal outputted from a predetermined amplifier among the at least one amplifier is greater than or equal to a reference voltage, the comparator unit outputs, from its output terminal, an output signal which is in line with the difference between the signal level and the reference voltage. The DC blocking unit is electrically connected, at its first terminal, to the output terminal of the comparator unit, and outputs, from its second terminal, a signal obtained by blocking the DC component of the output signal. The detection unit is electrically connected, at its input terminal, to the second terminal of the DC blocking unit, and outputs, from its output terminal, a control signal, which is in line with the signal level of the signal outputted from the predetermined amplifier, to a predetermined circuit capable of reducing the gain of the power amplifier circuit.