A rectifier circuit includes a first MOS transistor, a first capacitor configured to connect between a gate and a source of the first MOS transistor, and a switching circuit configured to supply a bias voltage to the first capacitor in response to a control signal. The high gain rectifier circuit also includes a second MOS transistor configured to imitate the first MOS transistor, a second capacitor configured to imitate the first capacitor, a dummy switching circuit configured to supply the bias voltage to the second capacitor in response to the control signal, and a generating circuit configured to generate the control signal based on a potential of the second capacitor.