发明授权
- 专利标题: Television tuner system
- 专利标题(中): 电视调谐器系统
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申请号: US09164558申请日: 1998-10-01
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公开(公告)号: US06400419B1公开(公告)日: 2002-06-04
- 发明人: Masaki Yamamoto
- 申请人: Masaki Yamamoto
- 优先权: JP9-278461 19971013
- 主分类号: H04N550
- IPC分类号: H04N550
摘要:
In a television tuner system, a printed board is disposed within a frame having a side plate. A tuner and an intermediate frequency circuit are disposed adjacent to each other on the printed board. The tuner has a mixer and a local oscillator. The intermediate frequency circuit includes at least a SAW filter having a plurality of terminals. A first ground conductor is formed between the tuner and the intermediate frequency circuit. A second ground conductor is formed at a peripheral edge of the printed board. The SAW filter is placed along the second ground conductor in such a manner that the terminals of the SAW filter are arranged substantially parallel to the side plate. The local oscillator is disposed substantially on a line extending from the arrangement of the terminals of the SAW filter. With this arrangement, the distance between the output terminals and the local oscillator is greater than that between the input terminal and the local oscillator. It is thus possible to inhibit local oscillation signals from being accidentally input into the output terminals of the SAW filter, which would otherwise cause the generation of interruption signals, and also to maintain the performance of the SAW filter by preserving its selectivity characteristics.
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