Appendixes
U8903A User’s Guide 145
Example of the IIR filter file format:
#Type: IIR
#Delay: 10
#Sections: [0.021888116917017919, 1, –1.8522189864275376,
0.93977145409560914, 1, 2, 1] [0.020670375338350408, 1,
–1.7491711051903651, 0.83185260654376658, 1, 2, 1]
The coefficients of the IIR filter are described as follows.
where A
x
= Denominator and B
x
= Numerator
0.021888116917017919 //Section 1: Gain
1
1 //Section 1: A
1
[0]
–1.8522189864275376 // Section 1: A
1
[1]
0.93977145409560914 //Section 1: A
1
[2]
1//Section 1: B
1
[0]
2//Section 1: B
1
[1]
1//Section 1: B
1
[2]
0.020670375338350408 //Section 2: Gain
2
1//Section 2: A
2
[0]
–1.7491711051903651 // Section 2: A
2
[1]
0.83185260654376658 //Section 2: A
2
[2]
1//Section 2: B
2
[0]
2//Section 2: B
2
[1]
1//Section 2: B
2
[2]
The IIR filter transfer function, H(z), is defined as:
where z = complex variable, N = number of sections, x = section number
H(z) = Gain
x
B
x
0 B
x
1z
1–
B
x
2z
2–
++
A
x
0 A
x
1z
1–
A
x
2z
2–
++
------------------------------------------------------------------------------------
x = 1
N