FREQUENCY SYNTHESIZER

摘要

PURPOSE:To obtain a frequency synthesizer which can fractionate the variation step of the oscillation frequency for the voltage control type oscillator and also can secure the constant fractionation at all times with use of the highly stable reference oscillator and without increasing particularly the division ratio of the variable division circuit. CONSTITUTION:The output of voltage control type oscillator 11 is divided via variable division circuit 12 and then given the phase comparison with the output of reference oscillator 14 throuth phase comparator 13. And this result of comparison is drawn out via loop filter 15 to be fed back to oscillator 11 in the form of the control voltage. Circuit 12 is constituted by giving the longitudinal connection to first variable divider 16 of division ratio, second variable divider 17 and rate multiplier 18 which generates Q-units of the output pulse to P-units of the input pulse. And division ratio k of divider 16 is switched by the output pulse.