PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

DTFT, DFT, ZT, and FFT 513

− 8

0.6

0.8

1

1.2

Magnitude

Phase angle in rad.

1.4

1.6

− 6 − 4 − 2 0

frequency W

2468

− 8 − 6 − 4 − 2 0246 8

−0.4

−0.2

0

0.2

0.4

frequency W

DTFT[f1(n)] = 1./(1-0.3*exp(-j.*W))

FIGURE 5.26

Plot of F 1 (ejW) over the range −2π < W < 2π of Example 5.2.

− 8

0

5

10

Magnitude

Phase angle in rad.

15

− 6 − 4 − 2 0

frequency W

2468

− 8 − 6 − 4 − 2 0246 8

− 2

− 1

0

1

2

frequency W

DTFT[f2(n)] = 1./(1-0.9*exp(-j.*W))

FIGURE 5.27

Plot of F 2 (ejW) over the range −2π < W < 2π of Example 5.2.