| 摘要 |
PURPOSE:To improve the S/N of a signal and waveform distortion by adopting the constitution that the 1st and 2nd basic circuits having a transfer function approximated by a specific function are connected in cascade to form a basic circuit and a means is used to form the titled unit combining the input signal via the basic circuit and the input signal not through the basic circuit in a prescribed ratio. CONSTITUTION:The 1st basic circuit 10 has a transfer function approximated by functions expressed in equation 1 or 2, where omegais an angular frequency of an input signal, T is a constant having the unit of time, and (k) is a constant. The 2nd end basic circuit 20 is constituted by connecting time axis conversion circuits 200, 300 before and after the circuit 10 in cascade. The circuits 10, 20 are connected in cascade to constitute the basic circuit 100. The input signal Si through the circuit 100 and a coefficient device 33 and the input signal not through them are added by an adder 34 and the said both signals are combined in a prescribed ratio to obtain an output signal So. Thus, a pre-emphasis circuit whose phase characteristic is linear emphasizing the amplitude of the signal at a middle or a high frequency and a de-emphasis circuit having an opposite amplitude characteristic to the amplitude characteristic of the pre-emphasis circuit and whose phase characteristic is matched with the said circuit over a wide frequency range are realized in this way.
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