A rectenna includes an antenna configured to receive a radio wave, a rectifier circuit configured to rectify the radio wave received by the antenna, a transmission line connected to the antenna and the rectifier circuit, and a modulation input circuit including a variable capacitance element. The variable capacitance element is connected at one end to a portion of the transmission line between an antenna connecting portion at which the antenna is connected to the transmission line and a rectifier circuit connecting portion at which the rectifier circuit is connected to the transmission line, and is configured such that the capacitance thereof varies in accordance with the voltage of a modulated signal wave input to the other end of the variable capacitance element.