| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress fractional spurious emissions caused in a fractional N PLL (Phase-Locked Loop) frequency synthesizer. <P>SOLUTION: The fractional N PLL frequency synthesizer configured to temporally switch the division number of a variable frequency divider between two or more integer values has a variable notch filter 8 capable of controlling a suppression frequency and an attenuation between a voltage-controlled oscillator 2 and a loop filter 7, thereby suppressing fractional spurious emissions. <P>COPYRIGHT: (C)2013,JPO&INPIT |
