PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

642 Practical MATLAB® Applications for Engineers

Example 6.16

Rerun Example 6.15 given by the script fi le multiban for the fi lter’s specs given by

a. 0.2 ≤ W ≤ 0.4, H(W) = 0.3

b. 0.6 ≤ W ≤ 0.8, H(W) = 0.6

c. Zero everywhere else, that is,

0 ≤ W < 0.2, H(W) = 0

0.4 < W < 0.6, H(W) = 0

0.8 < W ≤ 1, H(W) = 0

MATLAB Solution

The new fi lter’s specs translate in modifying the frequency–magnitude vectors of the

script fi le multiban as follows:

w = [0 .1 .2 .3 .4 .5 .6 .7 .8 1]

mag = [0 0 .3 .3 0 0 .6 .6 0 0]

The modifi ed script fi le multiban is executed and the resulting plots are shown in

Figure 6.67.

FIGURE 6.66
Multiband fi lter’s plots of Example 6.15.

0

0 0.1 0.2 0.3 0.4 0.5 0.6

Multiban filter using fir2 (with bartlett window)

Multiban filter using remez

Multiban filter using yulewalk

frequency W (in rad)

frequency W (in rad)

frequency W (in rad)

0.7 0.8 0.9 1

0.5

gain

gain

gain

1

0

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

1

0.5

1.5

0

1

0.5

1.5

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1