APPARATUS AND METHOD FOR CONTROLLING A FREQUENCY SYNTHESIZER USING OUTPUT OF DDS AS INPUT OF REFERENCE FREQUENCY OF PLL

摘要

PURPOSE: An apparatus and method for controlling a frequency synthesizer using output of DDS as input of reference frequency of PLL is provided to obtain the improvement money spurious property by exchanging the frequency stability and spurious property. CONSTITUTION: The multiplying value of PLL is set to the PLL be input the DDS output(S410). The phase increment is set based on the fixed multiplying value(S420). The frequency synthesis ratio and the given initial phase value is generated based on the fixed phase increment(S430). The multiplying value of PLL is not fixed to the given specific single valued. The arbitrary natural number is selected. The phase increment corresponding to the arbitrary natural number is calculated.