发明名称 |
Tunable notch filter for image frequency and conducted local oscillator leakage rejection |
摘要 |
A tunable notch filter for the front end of an RF receiver includes magnetically coupled input and output tunable stages each responsive to a tuning voltage provided thereto. Each of the input and output stages includes a respective series and parallel resonant circuit wherein the parallel resonant circuits are tuned to a selected RF frequency and the series resonant circuits are tuned to a frequency approximately equal to that of a local oscillator. By using the series resonant circuits to create a notch at a frequency approximating that of the local oscillator, conducted local oscillator leakage from the receiver's antenna is substantially reduced and local oscillator image frequency rejection is substantially improved.
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申请公布号 |
US4662001(A) |
申请公布日期 |
1987.04.28 |
申请号 |
US19850766161 |
申请日期 |
1985.08.15 |
申请人 |
ZENITH ELECTRONICS CORPORATION |
发明人 |
CRUZ, MICHAEL S.;VAUGHTER, HARMON P. |
分类号 |
H03H7/09;H04B15/06;(IPC1-7):H04B1/26 |
主分类号 |
H03H7/09 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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