The solution of the given problem (see Fig.
) can be described as follows:
•
Prerequisite for the application of this method is the knowledge of the
S-parameters of the fixtures.
•
Without de-embedding only the S-parameters of the unknown over-
all system can measured. Potential errors introduced by the fixtures
detoriate the accuracy of the measurement results.
•
The overall system can be decomposed into the subcomponents DUT
and fixture 1 & 2.
•
The S-parameters of the fixtures and DUT are internally converted to
T-parameters.
•
The inverses of the fixture T-parameters are multiplied from the left
and right by the overall system T-parameters.
•
The result describes the DUT exclusively and is converted back to S-
parameters.
In summary, it is necessary to provide the software with the S-parameters
(see section
) of the fixtures for the de-embedding task. The S-parameters
can either be made available by the supplier of the fixture or be determined
by the user. The determination of the these parameters is far from trivial and
can be done by simulation or by measurement (or a combination of both).
The Seunis software itself can be used to characterize the adapters, please
refer to section
8.2 The De-Embedding Dialog
Loading the S-parameters of the fixtures can be done via the
De-Embedding
Dialog
(see Fig.
). The dialog can be opened via the tool button
which
can be found in toolbar of the
Main Window
. If no de-embedding param-
eters are loaded, the button is grey and becomes green only after the S-
parameters are loaded.
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