Allpass Transfer Function If we denote the denominator polynomial of M(2) as DA/(二) DM(z)=1+d12+…+dM-12 M+1 then it follows that AM(z)can be written as -M AM(z)=± 2 Note from the above that ()jD is a pole of a real coefficient allpass transfer function, then it has a zero at z=le- jp Copyright C 2001, S K Mitra4 Copyright © 2001, S. K. Mitra Allpass Transfer Function • If we denote the denominator polynomial of as : then it follows that can be written as: • Note from the above that if is a pole of a real coefficient allpass transfer function, then it has a zero at AM (z) DM (z) M M M DM z d z dM z d z − + − − − = + + + + 1 1 1 1 1 ... ( ) AM (z) ( ) ( ) ( ) D z z D z M M M M A z − −1 =   = j z re −  = j r z e 1