Concepts and Features
R&S
®
ZNA
101
User Manual 1178.6462.02 ─ 12
Complex dimensionless quan-
tities:
S-parameters and ratios
Complex quantities with dimensions:
Wave quantities, Z-parameters, Y-
parameters, impedances, admittan-
ces
Real quantities:
Smith
ON (reflection coefficients S
ii
)
–
–
Polar
ON
–
–
Inverted Smith
ON (reflection coefficients S
ii
)
–
–
SWR
ON (reflection coefficients S
ii
)
–
–
Delay
ON (transmission coefficients S
ij
)
–
–
The default formats are activated automatically when the measured quantity is
changed.
5.3
Measurement Results
This section gives an overview of the measurement results of the network analyzer and
the meaning of the different measured quantities. All quantities can be selected in the
"Meas" softtool (function key Trace – [Meas]).
5.3.1
S-Parameters
S-parameters are the basic measured quantities of a network analyzer. They describe
how the DUT modifies a signal that is transmitted or reflected in forward or reverse
direction. For a 2-port measurement, the signal flow is as follows.
The figure above is sufficient for the definition of S-parameters but does not necessa-
rily show the complete signal flow. In fact, if the source and load ports are not ideally
matched, part of the transmitted waves are reflected off the receiver ports. An addi-
tional a
2
contribution occurs in forward measurements, and an a
1
contribution occurs in
reverse measurements. The 7-term calibration types Txx take these additional contri-
butions into account.
The scattering matrix links the incident waves a
1
, a
2
to the outgoing waves b
1
, b
2
according to the following linear equation:
Measurement Results
