| 摘要 |
PURPOSE:To obtain a variable attenuating aqualizer of simple circuit constitution. CONSTITUTION:In general, the transfer function of a variable equalizer is expressed by H(Z)=H0 [1-KF(Z)]/[1+KF(Z)]. Here, it is provided that Z is equal to e<jwt> and F(Z) is a rational function of (Z). The attenuation factor, which is proportion to the real number field of F(Z), can be veried by varying proportion coefficient K. Transforming the above equation results in H(Z)=Ho[1+{(-2aoK)/ (1+aoK)+ (-2KF1(Z))/(1+aoK)}/{1+(KF1(Z)/(1+aoK)}]. Here, ao is the constant term of the numerator of F(Z), and any constant term of F1(Z) is not included in the numerator of F1(Z). This equation is realized by multiplier 11 of coefficient Ho, adder 21, block 6 realizing transfer function F1(Z), and multipliers 51 to 54 of coefficients K/(1+aoK), -2ao, -1, and -2. Block 6 consists of delay units 61 and 62, multipliers 63 to 66, and adders 67 and 68. |
