R&S ZVL
GUI Reference
Channel Menu
Operating Manual 1303.6580.32-06
232
The idea of virtual embedding is to simulate the matching network and avoid using physical circuitry so
that the analyzer ports can be directly connected to the input and output ports of the DUT. The matching
circuit is taken into account numerically. The analyzer measures the DUT alone but provides the
characteristics of the DUT, including the desired matching circuit. This method provides a number of
advantages:
•
The measurement uncertainty is not impaired by the tolerances of real test fixtures.
•
There is no need to fabricate test fixtures with integrated matching circuits for each type of DUT.
•
Calibration can be performed at the DUT's ports. If necessary (e.g. for compensating for the effect
of a test fixture) it is possible to shift the calibration plane using length offset parameters.
Deembedding a DUT
Deembedding and embedding are inverse operations: A deembedding problem is given if an arbitrary real
network connected to the DUT is to be virtually removed in order to obtain the characteristics of the DUT
alone. Deembedding is typically used for DUTs which are not directly accessible because they are
inseparably connected to other components, e.g. for MMICs in a package or connectors soldered to an
adapter board.
To be numerically removed, the real network must be described by a set of S-parameters or by an
equivalent circuit of lumped elements. Deembedding the DUT effectively extends the calibration plane
towards the DUT ports, enabling a realistic evaluation of the DUT without the distorting network.
Deembedding can be combined with length offset parameters.
The simplest case of one-port deembedding can be depicted as follows:
The embedding/deembedding function in the
Virtual Transform
menu has the following characteristics:
•
Two-port networks can be applied to any of the DUT ports 1 or 2.
