| 摘要 |
PROBLEM TO BE SOLVED: To obtain a CATV (cable TV) tuner with a structure that prevents noises and an upstream signal from flowing to the downstream side and can prevent the occurrence of distortion of a downstream signal due to a CATV signal. SOLUTION: This CATV tuner 20 includes an input circuit 26 arranged in a tuner box 22, a first mixing circuit 42, a first oscillation circuit 44, a first intermediate frequency circuit 46, a second mixing circuit 48, a second oscillation circuit 50 and a second intermediate frequency circuit 52. The input circuit 26 includes a bandpass filter 28 arranged between an input terminal 24 and an upstream signal input terminal 32, and the input terminal 24 is connected to a distributor 34 through a highpass filter 30. One output side of the distributor 34 is subjected to processings such as filtering and amplification and then connected to the first mixing circuit 42, and the other output side is connected to a downstream signal output terminal 40 through a lowpass filter 36 and an amplifier 38. COPYRIGHT: (C)2004,JPO
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