| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a contactless IC card reader/writer having an effective receiving characteristic. <P>SOLUTION: The contactless IC card reader/writer is provided with a loop antenna for supplying power and a transmission signal to a contactless IC card by electromagnetic induction and acquiring a receiving signal from the contactless IC card by load variation, a resonance circuit part for resonating the loop antenna with required frequency, a radio transmission part for supplying power and transmission data to the loop antenna through the resonance circuit part, and a radio receiving part for acquiring a receiving signal from the loop antenna through the resonance circuit part and constituted so as to demodulate data from the contactless IC card by a demodulation circuit on the basis of the receiving signal. The resonance circuit part, the radio transmission part and the radio receiving part are connected through any one of a directional coupler, a circulator and an isolator. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
