发明授权
- 专利标题: Band-pass filter circuit
- 专利标题(中): 带通滤波电路
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申请号: US179193申请日: 1980-08-18
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公开(公告)号: US4361894A公开(公告)日: 1982-11-30
- 发明人: Hiroshi Kurihara , Tadayoshi Katoh
- 申请人: Hiroshi Kurihara , Tadayoshi Katoh
- 申请人地址: JPX Kanagawa
- 专利权人: Fujitsu Limited
- 当前专利权人: Fujitsu Limited
- 当前专利权人地址: JPX Kanagawa
- 优先权: JPX53-7490 19780126
- 主分类号: H03H7/06
- IPC分类号: H03H7/06 ; H03H11/04 ; H03L7/093 ; H03L7/10 ; H04B7/155 ; H04L27/22 ; H03D3/06
摘要:
A band-pass filter circuit comprising a band-pass filter for removing noise modulation components from an input signal comprising a carrier sine wave, a phase detector for detecting a phase difference between input and output signals of the band-pass filter, a loop filter supplied with the output from the phase detector, and automatic control means for effecting control by the output from the loop filter so that a difference between the frequency of the input sine wave and the center frequency of the band-pass filter is reduced to zero. For carrier recovery in a burst mode, the loop filter is selected for each particular case so that high-speed pulling-in is possible even if a narrow-band filter is employed as the band-pass filter for the removal of noise components. Also, high-speed and high-precision pulling-in is achieved when many bursts of different frequencies are applied in one frame period. Further, when common and individual frequency variations occur at the same time, high-speed pulling-in is also achieved for each burst.
公开/授权文献
- US6107563A Photoelectric converter having light diffusion layer 公开/授权日:2000-08-22
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