| 摘要 |
PROBLEM TO BE SOLVED: To prevent increase of amplitude variation and spurious radiation in a specific frequency due to an output phase in a signal generator including a DDS oscillator. SOLUTION: In the case of generating an output signal in a prescribed frequency by providing a first DDS oscillator 10 with a reference clock and frequency data from a second DDS oscillator (reference clock generating origin) 20 and an oscillator control means 40, a frequency of the reference clock to be outputted from the second DDS oscillator 20 is made controllable by the oscillator control means 40. When the reference clock is defined as a default frequency, whether or not the output signal of the first DDS oscillator 10 is integer/integer of the default frequency (for example, 1/integer) is discriminated, when the output signal is not integer/integer, the reference clock is set as the default frequency, and when the output signal is integer/integer, the reference clock is set as a frequency shifted from the default frequency by the prescribed frequency. COPYRIGHT: (C)2003,JPO
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