发明授权
US07570096B2 Direct digital synthesizer with variable reference for improved spurious performance
有权
具有可变参考的直接数字合成器,可提高杂散性能
- 专利标题: Direct digital synthesizer with variable reference for improved spurious performance
- 专利标题(中): 具有可变参考的直接数字合成器,可提高杂散性能
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申请号: US11861860申请日: 2007-09-26
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公开(公告)号: US07570096B2公开(公告)日: 2009-08-04
- 发明人: Nicholas G. Cafaro , Thomas L. Gradishar , Robert E. Stengel
- 申请人: Nicholas G. Cafaro , Thomas L. Gradishar , Robert E. Stengel
- 申请人地址: US IL Schaumburg
- 专利权人: Motorola, Inc.
- 当前专利权人: Motorola, Inc.
- 当前专利权人地址: US IL Schaumburg
- 主分类号: H03H11/26
- IPC分类号: H03H11/26
摘要:
Improvement of quantization errors that arise in a delay line with finite resolution. A direct digital synthesizer (DDS), which contains a numerically controlled oscillator (NCO) and a digital-to-phase converter (DPC), is placed in the feedback loop of a phase locked loop (PLL). The DDS is used as a fractional divider of the voltage controlled oscillator (VCO) frequency, such that the reference frequency of the DDS is made variable. Alignment of the edges provided by the DDS delay line may then be adjusted. Mismatch errors in the DDS delay line are reduced by utilizing independently tunable delay elements.
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