| 摘要 |
PURPOSE:To erase harmonic distortion by raising an FM demodulating signal to the n-th power, differentiating the n-th power of the FM demodulating signal once, adjusting the level of the differentiated value, adding the level-adjusted value to said demodulating signal, and then adding a signal obtained by differentiating the n-th power of the demodulating signal twice and adjusting the level of the demodulated signal to said added result. CONSTITUTION:An FM tuner is constituted by a front end 1, an intermediate frequency device 2, an FM demodulator 3, and a distortion cancelling circuit 4. A demodulated output S is raised to the n-th power 13 to obtain a signal S13. The signal S13 is differentiated 14 once, the differentiated signal S14 is level-adjusted 15 and outputted as a signal S15 and the signal S15 is added 11 to the signal S. On the other hand, the signal S13 obtained by raising the signal to the n-th power is differentiated 16 twice and outputted as a signal S16 and the signal S16 is level-adjusted 17 and outputted as a signal S17. The signal S17 is added to an output signal S11 from the adder 11 by an adder 12 and a signal S12 is outputted. Thus, a harmonic component distortion from the signal S is cancelled and reproducing suppressing the distortion can be attained.
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