| 摘要 |
PROBLEM TO BE SOLVED: To perform stable communication. SOLUTION: A communication control part 23 which writes and reads data to and out of an IC memory 213, applies ASK (amplitude shift keying) modulation to digital data by a modulating and demodulating circuit 232 amplifies the obtained ASK modulation signal by an amplifying circuit 2331, and sends the resulting signal by a coil antenna 236. According to the result of comparison between the output level of the amplifying circuit 2331 and a specific reference level, the power supply voltage from a transmission power supplying 2332 to the amplifying circuit 2331 is controlled. |
