| 摘要 |
PROBLEM TO BE SOLVED: To obtain a television TV reception circuit where a front end circuit of a television receiver is integrated and the output of an image frequency is suppressed. SOLUTION: A received broadcast signal is given to an integrated circuit 20 consisting of an analog circuit via a TV variable frequency tuning circuit 10. The integrated circuit 20 is provided with an AGC amplifier 21 and 1st and 2nd frequency mixers 22A, 22B, the 1st and 2nd frequency mixers 22A, 22B receive local signals with a phase difference of 90 deg. from aϕ/2 phase shift circuit 24 shifts a phase of an oscillated frequency fL0 and provide an output of an intermediate frequency that is a difference component between a frequency of the local signal and a frequency of a received channel. The intermediate frequency outputted from the 1st and 2nd frequency mixers 22A, 22B is fed respectively to a +π/4 phase shift circuit 25A and a -ϕphase shift circuit 25, outputs of them are added by an adder circuit 26 at an equal level and the sum is outputted to an intermediate frequency amplifier circuit 27 as a synthesized signal.
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