5.1.1 Ideal Frequency-Selective Fiters ◆ Ideal bandpass filter W<w<1 Hb J 0. others H(e") 丌-W w0 w7 5.1.1 Ideal Frequency-Selective Filters ◆Ideal bandpass filter ( ) 1 2 1, 0, jw c c bp w w w H e others    =   0 1 wc 1 − − wc  ( ) jw H e 1 2 wc 2 − wc