REALIZATION OF IIR FILTER USING DIRECT FORM -2:
THEORY:
The Direct form-II structure is an alternative to direct form-I structure.
It is more advantageous to use direct form-II technique than direct form-I, because it uses less number
of delay elements than the direct form-I structure.
In direct form-II, an intermediate variable is introduced and the given transfer function
is split into two, one containing only poles and the other containing only zeros.
The poles [that is, the output components y(n) or Y(z) which is the denominator part of the transfer
function] are realized first and the zeros [that is, the input components either x(n) or X(z),
which is the numerator part of the transfer function] second.
If the coefficient of the present output sample y(n) or the non-delay constant at
denominator is non unity, then transform it to unity. The systematic procedure is given as
follows:
TRANSFER FUNCTION H(Z):
d1: |
|
d2: |
|
d3: |
|
p0: |
|
p1: | |
p2: |
|
p3: |
REALIZATION OUTPUT:
