Teledyne LeCroy Eye Doctor II - Manual (Page 19)

Operator's Manual
overall response to the lower frequencies where signal components are detectable above the noise. If
this value is set to zero (the default) then no bandwidth limit is applied.
Auto BW and Boost for Auto have the same effect as Bandwidth Limit but instead of setting the band-
width, you set the maximum boost allowed. Eye Doctor II looks at the S- parameter responses and sets
up the low pass filter (see Bandwidth Limit above) at the frequency where one of the outputs has more
boost than the specified Boost for Auto. Boost for Auto can be set between 3 dB and 20 dB. The band-
width in use is reported back to the user.
Note: When emulating a passive fixture or channel, the S-Parameter system does not have any boost,
and the bandwidth in use is the highest bandwidth possible.
Fixture and Channel Dialogs
Use the De-embed Fixture, De-embed Channel or Emulate Channel buttons on the Emulate / De-embed
dialog to access the Fixture and Channel dialogs. These dialogs have identical functionality and differ only
in name. You will see the single-ended or differential version of the dialog depending on the Input selec-
tion made on the
Signal Input dialog.
Single-ended and differential input versions of the Fixture dialog.
The Channel dialog differs only in name.
1. Check the Use Ideal Fixture or Use Ideal Channel checkbox to use a perfect fixture or channel with
no loss.
2. Touch Browse to select the Touchstone format S-Parameter file representing the fixture or channel.
3. If using Differential inputs, choose the S-Parameter Format, either Single-Ended or Mixed Mode.
4. Assign to each Port a data column from the selected S-Parameter file. (This is useful for re-mapping
from the same S-Parameter file.)
5. Check the status of the file mapping. The indicator next to the Apply button should be green.
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