| 摘要 |
PURPOSE:To attain low spurious radiation in an output signal while keeping power consumption low in the frequency synthesizer employing a direct digital synthesizer. CONSTITUTION:An output of a direct digital synthesizer 1 is given to a frequency converter 19, in which the signal is mixed with a signal from a local oscillation source 17 at a mixer 16 and the frequency of the signal is converted into a high frequency. Then the converted output is used for a reference signal of a phase locked loop to decrease a frequency division ratio of a phase locked loop 8. Since the smaller the frequency division ratio is the, smaller the spurious radiation is, the spurious radiation in the output signal is reduced. |
