| 摘要 |
PROBLEM TO BE SOLVED: To provide an auxiliary antenna that can freely set extension or non-extension of a communication available area of an IC card even when no switch is provided in the IC card. SOLUTION: The auxiliary antenna 10 has a shape of card, the IC card receives a high frequency magnetic field from a reader/writer of a data communication system to produce an operating power and is located so that the contactless communication available area of the IC card capable of sending/ receiving a signal to/from the reader/writer can be extended. The auxiliary antenna 10 includes, a loop shaped antenna 11 and a capacitor 12 to form a resonance circuit; and a switch 13 to select a function state/a no function state of the loop antenna. Thus, the IC card itself has no switch to select the function state/the no function state of the loop antenna, an when the IC card is integrated with the auxiliary antenna, the IC card can freely select the range of the communication available area by means of the switch of the auxiliary antenna without the need for being set to/brought from a shield case. |
