Keysight InfiniiVision HD3 Series - Oscilloscope Bandwidth and Sample Rate

Acquisition Control 12
Keysight InfiniiVision HD3-Series Oscilloscopes User's Guide 163
Oscilloscope Bandwidth and Sample Rate
An oscilloscope's bandwidth is typically described as the lowest frequency at
which input signal sine waves are attenuated by 3 dB (-30% amplitude error).
At the oscilloscope bandwidth, sampling theory says the required sample rate is f
S
= 2f
BW
. However, the theory assumes there are no frequency components above
f
MAX
(f
BW
in this case) and it requires a system with an ideal brick-wall frequency
response.
Figure 26 Aliasing
Figure 27 Theoretical Brick-Wall Frequency Response
f
S
f
N
-3dB
Attenuation
Frequency
0dB