Patent ID: 6193164
Filing Date: 2001-02-27
Classification: G06K

Abstract:
An IC card which transmits and receives desired data sequences in non-contact transmission between a predetermined processor, said IC card comprising:an antenna for receiving a transmission signal from the processor;a demodulation circuit for retrieving a transmitted data sequence sent from the processor by demodulating the transmission signal received by said antenna;a reference signal forming circuit for forming a reference signal having the same frequency as a carrier of the transmission signal received by said antenna and phase-synchronized with the carrier;a modulation circuit for sending out a response data sequence corresponding to the transmitted data sequence from said antenna by modulating the reference signal with the response data sequence in a phase shift keying manner; anda power supply circuit for producing operating power by rectifying the transmission signal received by said antenna, wherein said demodulation circuit and said modulation circuit operate by the power produced by said power supply circuit.