Group Delay(群延迟,grd) t W=grd [H(e) delang heip) H(en)]=-d-Wnly then [(w)=na ◆ For ideal delay system argH(e)=-(arg[e n] W d The group delay represents a convenient measure of the linearity of the phase 1010 Group Delay(群延迟，grd ) ◆For ideal delay system ( ) ( ) arg ( )  jw jw d w H e H g d e w r d  = = −          d d  d wn n dw = − − = ( ) 0 arg jw d If H e wn   = − −    ( ) d then w n  = The group delay represents a convenient measure of the linearity of the phase. ( ) arg arg ( )    d d d jw jwn w H e e dw dw  − = − = −        