Patent ID: 8773207

Claim:
A semiconductor device comprising: a phase locked loop comprising a loop filter, and configured to output a clock signal; a first antenna configured to receive a first electromagnetic wave and output a first alternating current signal; a second antenna configured to receive a second electromagnetic wave and output a second alternating current signal; a battery configured to be charged wirelessly by the first alternating current signal supplied from the first antenna and the second alternating current signal supplied from the second antenna, and output a power supply voltage to the phase locked loop; and a control circuit configured to control charging and discharging of the battery, wherein a characteristic of the phase locked loop is switched in accordance with a time constant of the loop filter, wherein the first antenna is connected to both the phase locked loop and the battery, and wherein the first antenna is configured to supply the first alternating current signal to a first demodulation circuit so that the phase locked loop outputs the clock signal, and to a first power supply circuit so that the battery is charged wirelessly.