Analog and Digital Filters
653
FIGURE 6.76
Filter’s plot of part (a) of Example 6.20.
200
150
100
50
Ϫ50
0
Ϫ100
Ϫ150
Ϫ200
1
0.8
Magnitude
Angle in degrees
0.6
0.7
0.5
0.4
0.2
0.3
0.1
0
0
0.5
frequency W in rad.
Mag. of LPF using fir1/orderϭ18
Phase of LPF using fir1/orderϭ18
1
0
0.5
frequency W in rad.
1
0.9
FIGURE 6.77
Filter’s plot of part (b) of Example 6.20.
0.7
200
150
100
50
Ϫ50
Ϫ100
Ϫ150
Ϫ200
0
0.6
0.4
Magnitude
Angle in degrees
0.3
0.2
0.1
0
0
0.5
frequency w in rad.
Mag. of BPF using fir1/orderϭ8
Phase of BPF using fir1/orderϭ8
1
0
0.5
frequency w in rad.
1
0.5
Example 6.21
Design a 25th-order normalized FIR/LPF with a BW of 0.25 rad by using
a. The remez algorithm
b. fi r1 limited by a Hamming window
CRC_47760_CH006.indd 653
CRC_47760_CH006.indd 653
7/23/2008 2:27:01 PM
7/23/2008 2:27:01 PM