| 摘要 |
PURPOSE:To apply temperature compensation to cancellation of spur in a phase locked loop. CONSTITUTION:A phase detector 110 receives a reference frequency and a feedback frequency from a reference divider 100 and provides the output of an oscillator control signal representing the phase difference and the output of a predetermined frequency by a voltage controlled oscillator 270 via a loop filter 260. The outputted frequency is given to a prescaler 210 and the feedback frequency is outputted in cooperation with a main divider 120. An undesirable spur is produced in the phase locked loop. The spur is cancelled by a spur cancel network 250 and a cancel gain adjustment device 225. Furthermore, temperature compensation in the cancellation is conducted by a gain adjustment network 240. |
