| 摘要 |
<P>PROBLEM TO BE SOLVED: To compensate for the carrier component of a response signal transmitted from a tag and to improve the S/N of a response signal returned from the tag when radio communication of prescribed data is performed by a backscatter communication system. <P>SOLUTION: The information processing apparatus has the tag 10 that receives a carrier signal Sf having a frequency of 2.45 GHz and that modulates the carrier signal Sf with data to transmit a response signal Sf(D), and has a tag reader 20 that transmits the carrier signal Sf to the tag 10 and that receives and processes a response composite signal Sin returned from the tag 10. The tag reader 20 has a carrier compensating circuit 30 that compares the phase of the carrier signal Sf at the time of transmission with that of response composite signal Sin at the time of reception and that removes, on the basis of a comparison result, the carrier composite signal Sf' that is not synchronized with the phase of the carrier signal Sf at the time of transmission. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
