| 摘要 |
PROBLEM TO BE SOLVED: To provide a television tuner that can prevent image disturbance, in the case of receiving an analog television signal. SOLUTION: Upon the receipt of a digital television signal, the frequency of a local oscillation signal is made to match with the frequency of the digital television signal, two mixers 4a, 4b separately output two base-band signals whose phases are orthogonal to each other, the frequency of the local oscillation signal ids made to differed from the frequency of the analog television signal by a prescribed frequency, in the case of receiving a analog television signal and the two mixers 4a, 4b output separately two analog intermediate frequency signals whose frequency is converted into a prescribed frequency and whose phases differ by 90 degrees from each other, the phase of the analog intermediate frequency signals is shifted by 90 degrees, and the resulting signal is added to the other analog intermediate frequency signal.
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