PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

Analog and Digital Filters 653

FIGURE 6.76

Filter’s plot of part (a) of Example 6.20.

200

150

100

50

 50

0

 100

 150

 200

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/order
 18 Phase of LPF using fir1/order
 18

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

 50

 100

 150

 200

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/order
 8 Phase of BPF using fir1/order
 8

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