| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a contactless IC card and wireless system, capable of reliably extracting a carrier, even though a return level is increased to make carrier amplitude small when performing a reply to a reader-writer. <P>SOLUTION: The contactless IC card 10A includes: an antenna 10-1 configured to receive an electromagnetic wave and to induce an AC signal; a rectifier circuit 11 configured to rectify an AC signal from the antenna; a demodulating circuit 12 configured to demodulate received data from a rectified signal from the rectifier circuit; a carrier extraction circuit 13A configured to extract a carrier from the AC signal or the rectified signal and to generate an operation clock; a return data generating unit 151 configured to operate at the operation clock from the carrier extraction circuit and, after receiving received data from the demodulating circuit, output return data to a reader-writer; a modulating unit 14 configured to load-modulate the carrier of the AC signal with the return data; and a sensitivity control unit 152 configured to perform control so as to increase carrier extraction sensitivity of the carrier extraction circuit during a return period to the reader-writer. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
