| 摘要 |
PROBLEM TO BE SOLVED: To attain low costs, low current consumption, and high communication connection reliability by stable frequency precision without necessitating any high precise reference frequency generating part, or continuously operating AFC control. SOLUTION: A controlling part 8 reads an initial control signal corresponding to the temperature data of a temperature detecting part 12 from an initial signal storage part 13, and transmits it to an AFC part 6. The AFC part 6 transfers the initial control signal to a reference frequency generating part 5 for generating a corresponding reference frequency, and a corresponding station generating signal is supplied from a frequency generating part 4 to a receiving part 2 and a transmitting part 3. The AFC part 6 compares a signal obtained by converting a signal with frequency deviation from the base station of the receiving part 2 into an intermediate frequency with the output of the reference frequency generating part 5, changes the value of the control signal so as to be matched with the deviation, and controls the reference frequency. When the AFC control is completed, the control part 8 judges whether or not the electric field intensity and data error rate presumed value of the received signal fulfill a prescribed condition, and writes the temperature data and the value of the control signal obtained when the prescribed condition is fulfilled in the initial signal storage part 13. |
