Comb Filters For example the comb filter generated from the prototype lowpass FIR filter Ho(z) 1(1+z)has a transfer function L L (-)=H0(2)=;(1+2) Go(e )l has L notches Comb filter from lowpass prototype ato=(2k+1)T /L and L osk peaks at o=2兀M,1 O<k<L-1. in the frequency range 0<0<2 0.5 1.5 o/ Copyright C 2001, S K Mitra4 Copyright © 2001, S. K. Mitra Comb Filters • For example, the comb filter generated from the prototype lowpass FIR filter has a transfer function • has L notches at w = (2k+1)p/L and L peaks at w = 2p k/L, ( ) 1 2 1 1 − + z H0 (z) = ( ) ( ) ( ) L L G z H z z − = = 1+ 2 1 0 0 0  k  L −1 , in the frequency range 0  w 2p | ( )| 0 jw G e 0 0.5 1 1.5 2 0 0.2 0.4 0.6 0.8 1 w/p Magnitude Comb filter from lowpass prototype