| 摘要 |
PROBLEM TO BE SOLVED: To provide a frequency synthesizer which operates according to the principle of the fractional frequency synthesizer. SOLUTION: This frequency synthesizer has a phase control oscillator 1, a phase detector 2 that controls the oscillator 1, a loop filter 4 which is arranged on a control line between the phase detector and the oscillator, a reference frequency source 4 and a frequency divider 6 which is arranged between the reference frequency source and an input of the detector 1. The frequency divider is adjusted to a division ratio of entire numbers, has an adjusting means 7 which operates in multiple integration, controls the division ratio of the entire numbers of the frequency divider in the way that a fractional division ratio which corresponds to a desired fractional rational number division ratio can be generated by the means 7. Another input of the detector 2 is connected to an output of an oscillator via a mixer 8, an the mixer 8 operates according to the principle of a fractional number frequency synthesis where the difference between an output frequency of the oscillator and a reference frequency of the source 4 is formed. |
