Keysight Technologies 3458A Guide D'utilisation page 480

E High Resolution Digitizing With the 3458A
Figure E-1
Avoiding aliasing
To avoid signal distortion caused by aliasing, the effective sample interval must
meet the Nyquist criterion of 1/(2f
interval is the actual time between measurements selected. Therefore, through
the track-and-hold path or through the DCV path (explained in the next section),
the maximum signal frequency is 25 kHz or 50 kHz for 20 µs or 10 µs sample
intervals, respectively. If higher frequencies are present, then a low-pass filter of
bandwidth f
For sequential sampling, the effective sample interval is the time between
samples of the reconstructed wave form (refer to
effective sampling interval of less than 35 ns, the bandwidth of the
track-and-hold path, 12 MHz, eliminates most distortion caused by aliasing. If the
effective sample interval is greater than 35 ns and frequencies higher than 12 MHz
are present, an external filter is necessary as well.
480
In general, digital signal processing systems require a close look
at various functions beginning with the analog signal and
ending with results meaningful to the user.
or less should be inserted in the signal path.
0
). In direct sampling, the effective sample
0
Figure
Keysight 3458A User's Guide
E-2). If you select an