Patent ID: 8854191

Claim:
A semiconductor device comprising: a battery; and a chip comprising: a first antenna circuit; and a signal processing circuit for processing a signal received by the first antenna circuit and generating a signal to be supplied to the first antenna circuit, the signal processing circuit comprising: a rectifying circuit for rectifying the signal received by the first antenna circuit; a power supply circuit; and a control circuit, wherein the chip comprises: a first semiconductor film over a first insulating film; a second semiconductor film over the first insulating film; a second insulating film over the first semiconductor film and the second semiconductor film; a first gate electrode over the second insulating film, the first gate electrode overlapping the first semiconductor film; a second gate electrode over the second insulating film, the second gate electrode overlapping the second semiconductor film; a third insulating film over the first gate electrode and the second gate electrode; a first conductive film over the third insulating film, the first conductive film being electrically connected to the first semiconductor film; a second conductive film over the third insulating film, the second conductive film being electrically connected to the second semiconductor film; a fourth insulating film over the first conductive film and the second conductive film; a third conductive film over the fourth insulating film, the third conductive film being electrically connected to the first conductive film; and a fourth conductive film over the third conductive film, the fourth conductive film being electrically connected to the third conductive film, wherein the first antenna circuit comprises the fourth conductive film, wherein the second conductive film is electrically connected via an opening formed in the first insulating film, the second insulating film and the third insulating film to a fifth conductive film under the first insulating film, and wherein the control circuit is configured to supply an output voltage of the rectifying circuit to the battery when the output voltage of the rectifying circuit is larger than an output voltage of the battery and to supply the output voltage of the battery to the power supply circuit when the output voltage of the rectifying circuit is smaller than the output voltage of the battery.