A power supply circuit includes a switching element coupled in a current path between an input terminal and an output terminal and includes a smoothing capacitor coupled between the output terminal and a ground. A bypass capacitor is coupled between the input terminal and the ground. An antenna element shares the ground with the power supply circuit. A frequency filter having a stop band that is an operating frequency band of the antenna element is inserted in series in at least either a current path between the switching element and the smoothing capacitor or a current path between the bypass capacitor and the switching element. It is possible to suppress deterioration of wireless communication quality due to noise caused in a DC-DC converter.