Digitalisation - Signals, Processes, and Systems - page 295

Time domain

1,00
0,75
0,50
0,25
0,00
-0,25
4,0
3,5
3,0
2,5
2,0
1,5
1,0
0,5
0,0
4,0
3,5
3,0
2,5
2,0
1,5
1,0
0,5
0,0
-0,5
-1,0

Analog signal(Si-function)
Bandwidth nearly10 Hz;

Sampling frequency

Digital signal(Si-function); discrete values

50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950

ms

F requency domain

0,150
0,125
0,100
0,075
0,050
0,025
0,000
-0,025
0,30

Analog signal(Si-function)
Bandwidth nearly10 Hz;

0,25

Sampling frequency

0,20

0,15

0,10

0,05

0,00
0,0200
0,0175
0,0150
0,0125
0,0100
0,0075
0,0050
0,0025
0,0000

Digital signal(Si-function); discrete spectrum

25 50 75 100 125

Hz

Illustration 199: Periodic spectrum of frequency band limited signals

At the top you see an analog signal (Si-function) with a frequency band limited to roughly 10 Hz. With a
sampling rate of 32 Hz there is hardly any overlapping of adjacent frequency bands.