| 摘要 |
PURPOSE: A transfonder, and a device or a card having the transfonder are provided to increase a usage available distance of a transfonder and prevent use of a transfonder undesired by a user. CONSTITUTION: An antenna coil(60) receives a signal from a reader. A capacitor(61) constructs a parallel LC circuit with the antenna coil(60). An RFID(Radio Frequency Identification Chip)(64) receives a signal received from the antenna coil(60), creates corresponding information and transmits it to the antenna coil(60). A controller(600A) relays signal exchange between the antenna coil(60) and the RFID(64) and relays power to the RFID from a device in which a transfonder is mounted or from a battery. A switch(62) is connected in parallel to the parallel LC circuit and switched on/off by a signal coming from the controller(600A).
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