| 摘要 |
PURPOSE:To provide always a linear phase characteristic to any input signal level by controlling the gain of a noncyclic filter including a delay element in response to an input signal level. CONSTITUTION:A signal (a) which is a normalized signal inputted to an input terminal 11 in terms of amplitude 1, becomes a signal (b) via a delay element 12 and becomes a signal (c) via a delay element 13. Further, the signal (c) becomes a signal (d) via a variable gain element 14 and a signal (e) is obtained at an output of an inverting element 15. On the other hand, the signal (b) outputted from the delay element 12 is inputted to a gain element 17 and becomes a signal (g). Further, the input signal (a) becomes a signal (h) via a variable gain element 18 and a signal (i) is obtained at an output of an inverting element 19. A signal level detection element 16 outputs a control signal (f) in response to the level of the signal (b) outputted from the delay element 12 and the control signal (f) controls the gain A of the variable gain elements 14, 18. The signals e, g, i are added at an adder element 20, and a signal (j) is outputted from an output terminal 21. |
