DTFT, DFT, ZT, and FFT 529
0 5 10 15
− 2
− 1
0
angle [DFT[fn(n)]]
1
2
frequency W in rad.
0 5 10 15
0
20
abs [DFT[f(n)]]
40
60
frequency W in rad.
DFT[f1(n)] + DFT[f2(n)] + DFT[f3(n)] versus W
FIGURE 5.42
Plots of magnitude and phase angle of the sums of DFT of f 1 (n), f 2 (n), and f 3 (n) of Example 5.9.
FIGURE 5.41
Plots of angleDFT of f 1 (n), f 2 (n), and f 3 (n) of Example 5.9.
0 5
0.5
0
− 1
−0.5
2
0
angle [DFT[f3(n)]]
angle [DFT[f2(n)]]
angle [DFT[f1(n)]]
− 2
0
1
(^1015)
015 015
015 0
frequency W in rad.
15
W
W
[Phases of the DFTs of f1(n), f2(n) & f3(n)] versus W