132
Keysight InfiniiVision 1200 X-Series and EDUX1052A/G Oscilloscopes User's Guide
13
Acquisition Control
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.
However, digital signals have frequency components above the fundamental
frequency (square waves are made up of sine waves at the fundamental frequency
and an infinite number of odd harmonics), and typically, for 500 MHz bandwidths
and below, oscilloscopes have a Gaussian frequency response.
Figure 22
Theoretical Brick-Wall Frequency Response
[
H
[
C
"(Y7
6iiZcjVi^dc
;gZfjZcXn
%Y7
