| 摘要 |
PURPOSE: To quickly switch the frequency in fine steps by suppressing the occurrence of an unnecessary wave owing to the quantization noise of a direct digital synthesizer. CONSTITUTION: A 90 deg. hybrid 8 and a single side band mixer 9 are inserted into a phase locked oscillation loop, and the output of the direct digital synthesizer 4 is supplied to the single side band mixer 9. The signal obtained by dividing the frequency of the reference frequency signal from a reference signal source 5 by a frequency divider 7 is supplied to a phase frequency comparator 3. |
