Concepts and features
R&S
®
ZNA
207
User Manual 1178.6462.02 ─ 20
The sign of the phase shift is determined as follows:
●
A positive offset parameter causes a positive phase shift of the measured parame-
ter and therefore reduces the calculated group delay.
●
A negative offset parameter causes a negative phase shift of the measured param-
eter and therefore increases the calculated group delay.
4.6.1.7
Offset parameters for balanced ports
The offset parameters can be used for balanced port configurations:
●
Offset parameters must be assigned to both physical ports of a logical port.
●
"Auto Length" corrects the length offset of both physical ports of a logical port by
the same amount.
4.6.2
Embedding and deembedding
The R&S
ZNA allows you to define virtual networks to be added to/removed from the
measurement circuit for a DUT with single ended or balanced ports. This concept is
referred to as embedding/deembedding.
The embedding/deembedding function has the following characteristics:
●
Embedding and deembedding can be combined with balanced port conversion: the
(de-)embedding function is available for single ended and balanced ports.
●
A combination of four-port and two-port networks (not necessarily both) can be
applied to balanced ports; two-port networks can be applied to single ended ports.
●
A combination of four-port and two-port networks can be applied to any pair of sin-
gle-ended ports. Moreover it is possible to combine several port pairs in an arbi-
trary order (port pair de-/embedding).
●
Single-ended and/or balanced port (de-)embedding can be combined with ground
loop (de-)embedding. A ground loop models the effect of a non-ideal ground con-
nection of the DUT.
●
Transformation networks can be defined by a set of S-parameters stored in a
Touchstone file or by an equivalent circuit with lumped elements.
●
The same networks are available for embedding and deembedding.
4.6.2.1
Embedding a DUT
To be integrated in application circuits, high-impedance components like Surface
Acoustic Wave (SAW) filters are often combined with a matching network. To obtain
the characteristics of a component with an added matching network, both must be inte-
grated in the measurement circuit of the network analyzer.
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, includ-
ing the desired matching circuit.
Offset parameters and de-/embedding
