| 摘要 |
PURPOSE:To decrease change in amplitude even when an amount of delay is changed by connecting a delay section and an amplitude correcting section in cascade and setting a weight coefficient value at the amplitude correcting section to a square of the weight coefficient value of the delay section so as to correct an amplitude distortion generated at the delay section by the amplitude correcting section. CONSTITUTION:The amount of delay of delay lines 3, 4 of the delay section 10 is set respectively to T, 2T and the amount of delay of delay lines 13, 14 of the amplitude correcting section 20 is set respectively 2T, 4T being two times those of the amounts T, 2T. Suppose that no signal delay exists other than coefficient weight circuits 7, 17a, 17b and a fixed attenuator 15, no time delay exists other than the delay lines, and let the coefficient of the coefficient weight circuit 7 be (l), and the coefficient combining the coefficients of the circuits 17a, 17b and the fixed attenuator 15 be (k), then the overall amplitude characteristic is the addition of the amplitude characteristics of the delay section 10 and the amplitude correcting section 20. The coefficient weight circuits 7, 17a, 17b are interlocked mutually and have the same coefficient (l), then the relation of k=l<2>/2 is obtained when the coefficient of the fixed attenuator is 0.5. Thus, the term in which the amplitude is changed against frequencies in the range of l<1/2 becomes very small. Then, only the amount of delay is changed without amplitude change. |
