OSCILLATOR AND A TUNING METHOD OF A LOOP BANDWIDTH OF A PHASE-LOCKED-LOOP

摘要

There is provided an oscillator including: a reference signal generator that generates a reference signal having a reference frequency; a phase comparator that outputs a voltage in accordance with a phase difference between the reference signal and a feedback signal; a loop filter that receives a voltage output from the phase comparator, and gain-adjusts a voltage output from the phase comparator by means of an external control signal; a voltage controlled oscillator that oscillates an output signal at a frequency in accordance with an adjusted signal having been gain-adjusted by the loop filter; and a frequency divider that feeds back a frequency-divided signal resulting from frequency-dividing the output signal, to the phase comparator as the feedback signal.