预期目标怎么写专利名称:Local oscillator feedthru cancellation circuit
and method therefor乒乓球练习
发明人:White, Charles R.
楚河汉界申请号:EP89110919.1
常宁公主
申请日:19890616
公开号:EP0347761A3
公开日:
19900606
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摘要:A method and an apparatus are disclod for cancelling local oscillator (LO)feed thru in an intermediate frequency (IF) transmission circuit (31). The apparatus includes first and cond mixers (15, 17) for receiving local oscillator (LO) and
intermediate frequency (IF) signals. The mixers (15, 17) are operable to upconvert the intermediate frequency (IF) signal while passing an attenuated and pha shifted portion of the local oscillator (LO) signal. Bias regulation circuitry (21, 23) is provided for regulating the attentuation and pha shift of the local oscillator (LO) signal portion pasd by at least one of the mixers (15, 17) such that the local oscilla t or (LO) signal portions are combinable to cancel each other. A coupler circuit (19) is provided for combining the mixer outputs such that the local oscillator (LO) signal portions are substantially cancelled and an upconverted intermediate frequency (IF) signal remains. The bias regulation circuitry (21, 23) may be lf-correcting to optimize cancellation of the local oscillator (LO) signal portions (Fig. 2).
非洲鼓教案申请人:Hughes Aircraft Company
地址:7200 Hughes Terrace P.O. Box 45066 Los Angeles, California 90045-0066 US 国籍:US
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代理机构:Witte, Alexander, Dr.-Ing.
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