发明名称 |
FRACTIONAL-N FREQUENCY SYNTHESIZER AND METHOD THEREOF |
摘要 |
The present relates to a fractional-N frequency synthesizer improving noise characteristics and a method thereof. The fractional-N frequency synthesizer includes a reference oscillator that generates a reference frequency signal; a sigma-delta modulator that generates a desired decimal value based on the reference frequency signal; a divider that divides a voltage controlled oscillation frequency signal; first to M phase/frequency detectors that detect a difference in phase and frequency between the reference frequency signal and the divided voltage controlled oscillation frequency signal; first to M charge pumps that are connected to each of the phase/frequency detectors in series and charges or pumps charge amount according to output signals from each of the phase/frequency detectors; a loop filter that controls the amount of supplied current based on output signals from the charge pumps to filter low-pass frequency components; and a voltage controlled oscillator that is oscillated in response to the output signal from the loop filter and generates voltage controlled oscillation frequency signals.
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申请公布号 |
US2010321120(A1) |
申请公布日期 |
2010.12.23 |
申请号 |
US20090563903 |
申请日期 |
2009.09.21 |
申请人 |
SAMSUNG ELECTRO-MECHANICS CO., LTD. |
发明人 |
KIM YOO HWAN;NA YOO SAM;JO BYEONG HAK |
分类号 |
H03L7/08 |
主分类号 |
H03L7/08 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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