摘要 |
A non-contact IC card system capable of improving the data transmission rate and communication range without considerably enlarging the frequency band of a signal to be put to use. An AM-modulated signal (1F) from a reader writer (200) is received by a resonance circuit (6) of an IC card (100), and an IC card driving power source is produced therefrom in a rectifying section (8). In addition, it is demodulated in an AM demodulating circuit (10) and decoded in a decoder (13), thereby presenting reception data (10). On the other hand, when data (1J) is transmitted from the IC card (100), a characteristic of a regulator (9) for stabilizing an operating voltage of the resonance circuit (6) is altered on the basis of a signal encoded in an encoder (11) so that the signal is transmitted as an AM-modulated signal (1P) to the reader writer (200).
|