Digitalisation - Signals, Processes, and Systems - page 296

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

Analog signal

Sampling frequency

Digital signal

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

ms

Frequency domain

0,050
0,045
0,040
0,035
0,030
0,025
0,020
0,015
0,010
0,005
0,000
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0,0
0,01

Analog signal

Sampling frequency

0,01

Digital signal 0,01

0,00

0,00

0 25 50 75 100 125 150 175 200 225 250

Hz

Illustration 200: Sampling Principle: at the borderline of the overlapping of adjacent frequency bands

Here the bandwidth of the analog signal is roughly 30 Hz, the sampling frequency is 64 Hz. It can be
clearly seen that the limiting case of “non-overlapping” of periodic spectra is practically given here.