Teledyne LeCroy Eye Doctor II - Manual (Page 20)

Eye Doctor II Software
6. View Response to plot the characteristics of the fixture or channel as it will appear after import.
7. Touch Apply to build the configuration.
Note: S-Parameter files should cover the frequency range up to (at least) 1/2 the oscilloscope's sample
rate. For example, if the S-Parameter file only covers up to 10 GHz, then the oscilloscope sample rate
should be 20 GS/s. When the fixture or channel is being emulated, there is little effect. However, if the fix-
ture or channel is being de-embedded, then the S-Parameter matrix must be inverted. If it does not have
data up to half the oscilloscope's sample rate it can cause problems. For this reason, this requirement is
particularly important when de-embedding.
View Response
The View Response button on the Fixture and Channel Menus allows you to view a magnitude or phase
plot for a selected S-Parameter following Touchstone file import and association with a channel or fixture.
1. Choose which S-Parameter (row from the original file) to view.
2. Choose to view the Magnitude or Phase of that S-Parameter.
PLEASE NOTE THE FOLLOWING:
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For 4 port S-Parameter files, you can view either the Single-Ended or Mixed Mode S-Parameters
using the View Mode control.
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You can use a Math trace to Zoom the S-Parameter plot last viewed. Do this by selecting EDrResp
as the source for the zoom function. This enables you to view a S-Parameter plot on the full grid
and use cursors on the trace.
Touchstone File Format
Touchstone is a file format used for specifying S-parameters. It is a standard that is commonly adopted
by vector network analyzers (VNAs), time-domain network analyzers (TDNA) and EDA tools such as micro-
wave simulators.
Touchstone files must meet the following specification:
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The extension must be in the form .s[N]p where [N] corresponds to the number of ports in the
device. For example, a two port S-parameter file has an extension ".s2p".
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Lines cannot be longer than 2000 characters.
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