| 摘要 |
PROBLEM TO BE SOLVED: To eliminate a beat disturbing wave caused by a local oscillation signal for synchronization detection received by a video detection circuit and a local oscillation signal for frequency conversion. SOLUTION: The intermediate frequency circuit includes: a mixer circuit 1 for receiving the local oscillation signal for frequency conversion and outputting an intermediate frequency signal; a SAW filter 6 for receiving the intermediate frequency signal; and a video detection circuit 8 placed at a post- stage of the SAW filter and applying synchronization detection to the intermediate frequency signal, and a low pass filter 5 for passing the intermediate frequency signal and attenuating the local oscillation signal is interposed between the mixer circuit 1 and the SAW filter 6. COPYRIGHT: (C)2004,JPO
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