| 摘要 |
PROBLEM TO BE SOLVED: To provide the inexpensive reference signal generating circuit capable of saving an installation space that stably generates plural reference signals from plural kinds of burst signals. SOLUTION: The generating circuit is provided with 1st and 2nd voltage controlled oscillators 11, 15 whose oscillated frequency is changed in response to a signal given to a control terminal, a 1st frequency divider 14 that applies 1/j frequency division to an output of the 1st oscillator 11, a 2nd frequency divider 16 that applies 1/k frequency division to an output of the 2nd oscillator 15, a 1st phase comparator 17a that compares phases of output signals of the 1st and 2nd frequency dividers 14, 16, a 1st low pass filter 17b that smoothes an output of the 1st phase comparator 17a and feeds back the smoothed signal to a control terminal of the 2nd oscillator 15, a 2nd phase comparator 19a that compares a phase of an output signal of the 2nd oscillator 15 with a phase of a burst signal, and a 2nd low pass filter 19b that smoothes an output of the 2nd phase comparator 19a and feeds back the smoothed signal to a control terminal of the 1st voltage controlled oscillator 11, and a desired reference frequency signal is obtained from an output of the 2nd voltage controlled oscillator 15.
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