| 摘要 |
PROBLEM TO BE SOLVED: To provide a tuner for a CATV for reducing power consumption and for improving the distortion of a signal. SOLUTION: A tuner is provided with a receiving part for receiving a signal introduced from a CATV station by an HPF1, and in the receiving part, the signal is attenuated by a PIN attenuator circuit 33 with a gain based on the signal level, and amplified across a wide frequency band by a buffer amplifier 35, and high frequency components are amplified by a high frequency amplifier 32, and converted into desired intermediate frequencies by a frequency converting circuit constituted of oscillation circuits 7 and 8 and 13 and mixing circuits 6 and 28, and the signal is IF-amplified by an IF amplifier 19, and outputted from a terminal 12. Thus, the input signal from the circuit 33 to the post-amplifiers 32 and 35 can be prevented from being turned into a high level. Therefore, any signal distortion at the time of amplification can be improved, and supply currents to the amplifier can be reduced.
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