5.1.1 Frequency Response Phase and Group Delay input signal Frequency response H(el) modified in Y(eo)=lH(eo)X(em） a useful way, Ye)desirable Effect of H(ei) 十 Magnitude response (gain)H(ei) modified in a deleterious Y(ei-H(ei)X(e) manner distortions Effect of |H(eo刃 ◆Phase response(phase shift)∠H(eo) 有害的 失真 ∠Y(eo)=∠H(eo+∠X(eo) 16 Effect of∠H(eio)5.1.1 Frequency Response Phase and Group Delay ( ) ( ) ( ) j j j Y e H e X e    = ( ) ( ) ( ) j j j Y e H e X e    =  ◆Phase response (phase shift) ( ) H ej ( ) ( ) ( ) j j j Y e H e X e  = +    ( ) ◆ H ej Frequency response ( ) ◆Magnitude response H ej (gain) distortions modified in a useful way, system input signal 16 Y(e j) desirable + modified in a deleterious manner Effect of H(ej) Effect of |H(ej)| Effect of ∠H(ej) 有害的 失真