| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that it is difficult to provide long-distance communication because of the decrease of an internal voltage caused by the load switch ON of a load modulation system in the up link of a data carrier. SOLUTION: EOF in a transmitting instruction signal 50 from a reader/writer is detected and a useless demodulation circuit 3 during the up link period of the data carrier is stopped so that total internal resistance can be decreased, namely, a degree of decrease in the internal voltage according to a time constant in the ON state of a transistor 6 for load switch is relaxed. Thus, the data carrier can be operated by low power and long-distance communication is provided. |
