Patent ID: 8242889

Claim:
A radio-frequency identification (RFID) tag comprising: a battery that stores therein electricity and supplies the electricity to the RFID tag; an antenna that receives radio waves transmitted from a reader/writer; a demodulating unit that demodulates the radio waves received by the antenna; an electricity generating unit that generates electricity based on the radio waves received by the antenna, and supplies the electricity to the RFID tag; an electricity storage determining unit that determines whether electricity is stored in the battery; an electricity supply switching control unit that, when the electricity storage determining unit determines that electricity is stored in the battery, selects a connection of a circuit to operate the RFID tag with the electricity supplied from the battery; and an electricity generating unit switching control unit that, when the electricity storage determining unit determines that electricity is stored in the battery, selects a connection of a circuit to input all the radio waves received by the antenna to the demodulating unit by switching connection of a send backscatter switch used for sending reflected waves to a reader/writer.