| 摘要 |
<P>PROBLEM TO BE SOLVED: To increase energy transmission efficiency and extend a communication distance, with contactless power transmission from a reader device to a tag in a data communication system for performing data transmission therebetween. <P>SOLUTION: A coil antenna 26 of a reader device 10 performs transmission with a carrier frequency f. A tag 12 receives the transmission signal by a coil antenna 40, and replies from the coil antenna 40 by making a reply data to respond to the transmission signal correspond to a spread code sequence, and by performing load modulation according to the spread code sequence. After receiving the reply signal by the coil antenna 26, the reader device 10 performs correlation processing on the reply signal. The coil antenna 26 of the reader device 10 is commonly used for transmission and reception, and constitutes an LC resonance circuit tuned to the carrier frequency f. Between the coil antennas 26 and 40, resonance coils 38, 50 are provided. <P>COPYRIGHT: (C)2012,JPO&INPIT |
