| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric wave beacon capable of easily monitoring transmission frequency. SOLUTION: An electric wave beacon is provided with a carrier wave generator 4 multiplying a reference frequency from an internal reference generator 13 to generate a carrier wave having a predetermined carrier frequency, and transmits this carrier wave superposed by the data signal to the outside. The electric wave beacon comprises: a dividing circuit 16 generating a signal TI to be inspected having lower frequency by dividing the reference frequency; a time interval comparator circuit 17 comparing the signal TI to be inspected with the reference signal TO received from the outside to detect a time difference between these signals; and a control part 10 determining whether the operating state of the reference generator 13 is proper or not based on the detected time difference, and performing error processing when the operating state is not proper. COPYRIGHT: (C)2008,JPO&INPIT
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