发明授权
US06933984B2 Television tuner which maintains UHF band tuning circuit bandwidth constant in low to high band range
失效
电视调谐器,保持UHF频段调谐电路带宽在低到高频带范围内恒定
- 专利标题: Television tuner which maintains UHF band tuning circuit bandwidth constant in low to high band range
- 专利标题(中): 电视调谐器,保持UHF频段调谐电路带宽在低到高频带范围内恒定
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申请号: US09995544申请日: 2001-11-28
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公开(公告)号: US06933984B2公开(公告)日: 2005-08-23
- 发明人: Masaki Yamamoto , Akira Yamamoto
- 申请人: Masaki Yamamoto , Akira Yamamoto
- 申请人地址: JP Tokyo
- 专利权人: Alps Electric Co., Ltd.
- 当前专利权人: Alps Electric Co., Ltd.
- 当前专利权人地址: JP Tokyo
- 代理机构: Brinks Hofer Gilson & Lione
- 优先权: JP2000-367752 20001129
- 主分类号: H03J3/06
- IPC分类号: H03J3/06 ; H04B1/18 ; H04B1/26 ; H04N5/44 ; H04N5/50
摘要:
A tuning circuit's bandwidth is maintained almost constant throughout a UHF low to high band range so as to prevent interference by a neighboring channel, particularly in receiving high band television signals, and also to improve NF in receiving low band television signals, eliminating a difference in NF between channels. To realize this, a UHF tuner comprises: a UHF tuning circuit which has a varactor diode first and second inductance elements serially interconnected and connected in parallel with the varactor diode, where the varactor diode 11a varies a tuning frequency within a prescribed frequency range in the UHF band; and impedance means which is serially inserted between an input terminal and the junction of the two inductance elements, where the impedance by the impedance means increases as a frequency increases within the prescribed frequency range in the UHF band.
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