发明授权
- 专利标题: Synchronous detector and methods for synchronous detection
- 专利标题(中): 同步检测器和同步检测方法
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申请号: US223223申请日: 1994-04-05
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公开(公告)号: US5596606A公开(公告)日: 1997-01-21
- 发明人: Leo Montreuil
- 申请人: Leo Montreuil
- 申请人地址: GA Norcross
- 专利权人: Scientific-Atlanta, Inc.
- 当前专利权人: Scientific-Atlanta, Inc.
- 当前专利权人地址: GA Norcross
- 主分类号: H04N5/455
- IPC分类号: H04N5/455 ; H03C3/04 ; H03C3/40 ; H03D1/22 ; H03D1/24 ; H03D3/00 ; H03D3/24 ; H04L27/00 ; H04L27/02 ; H04L27/06 ; H04L27/38 ; H04N5/44
摘要:
A synchronous detector has first and second mixer circuits and a voltage controlled oscillator. The voltage controlled oscillator provides a local oscillator signal directly to the second mixer circuit and indirectly to the first mixer circuit through a phase transformer. The output of the first and second mixer circuits are combined in combiner circuitry to produce a jitter cancelled output signal. The jitter cancelled output signal is filtered in a loop filter and applied to the voltage controlled oscillator to control the frequency and phase of the local oscillator signal. The combiner circuitry includes a summer and a jitter cancellation filter. The jitter cancellation filter is preferably a high pass filter matched to spectrum of the signal detected. The output of the first mixer circuit is passed through the high pass filter into one input of the summer while the output of the second mixer circuit is passed to the second input of the summer. The output of the summer is passed to the loop filter.
公开/授权文献
- US4904489A Package for convection heating of food 公开/授权日:1990-02-27
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