| 摘要 |
PURPOSE:To eliminate phase distortion and to improve time responsiveness by using a DLPF which has linear phase characteristics and is not cyclic. CONSTITUTION:A digital signal from an AD converter 1 is supplied to the DLP19 through an absolute value calculator 2. This DLPF19 consists of the delay circuit composed of (m) sets of delay devices 20, adder and subtracter 21 feedback circuit including a delay device 26, and coefficient device 17. The adder and subtracter 21 adds the output of the absolute value calculator 2 and the output of the delay device 26 together and subtracts the output of the delay device 20 from the sum. The output of the adder and subtracter 21 is divided by (m) through the coefficient device 17. The phase characteristics of the DLPF19 formed as mentioned above are linear, so phase distortion is eliminated. Further, the DLPF19 is not cyclic, so the time responsiveness is improved. |
