| 摘要 |
PROBLEM TO BE SOLVED: To provide a tuner circuit which incorporates a circuit capable of facilitating adjustment work for characteristics of a pre-filter on the pre-stage of a frequency conversion circuit. SOLUTION: The tuner circuit comprises: a first frequency conversion circuit 22 to which a high frequency signal selected by a pre-filter 10 and a local oscillation signal generated by a local oscillator 30 are input, and which outputs a frequency component of a difference; an intermediate frequency filter 23 which outputs a desired intermediate frequency signal out of output signals of the first frequency conversion circuit; a second frequency conversion circuit 25 which is added for passing through the high frequency signal selected by the pre-filter at the time of pre-filter characteristic adjustment, to which the high frequency signal selected by the pre-filter and a local oscillation signal are input, and which outputs a frequency component of a difference; and an amplifier 24 which selects either the intermediate frequency signal output from the intermediate frequency filter or the output signal of the second frequency conversion circuit, and amplifies and outputs the selected signal. COPYRIGHT: (C)2007,JPO&INPIT
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