Concepts and features
R&S
®
ZNA
121
User Manual 1178.6462.02 ─ 20
Examples for special points in the inverted Smith chart:
●
The magnitude of the reflection coefficient of a short circuit (Y = infinity, U = 0) is
one, its phase is –180 deg.
●
The magnitude of the reflection coefficient of an open circuit (Y = 0, I = 0) is one, its
phase is zero.
4.2.3.3
Measured quantities and trace formats
The analyzer allows any combination of a display format and a measured quantity. The
following rules can help to avoid inappropriate formats and find the format that is ide-
ally suited to the measurement task.
●
All formats are suitable for the analysis of reflection coefficients S
ii
. The formats
"SWR", "Smith" and "Inv Smith" lose their original meaning (standing wave ratio,
normalized impedance or admittance) if they are used for transmission S-parame-
ters, ratios and other quantities.
●
For complex "Impedances", "Admittances", "Z-parameters", and "Y-parameters"
generally a Cartesian format or the polar format is suitable.
●
For the real valued
, one of the Cartesian formats "Lin Mag" or
"Real" should be used. In complex formats, real numbers represent complex num-
bers with zero imaginary part.
The following table gives an overview of recommended display formats.
Complex dimensionless quan-
tities:
S-parameters and ratios
Complex quantities with dimensions:
Wave quantities, Z-parameters, Y-
parameters, impedances, admittan-
ces
Real quantities:
Lin Mag
ON
ON (default for Z-parameters, Y-param-
eters, impedances, admittances)
ON (default)
dB Mag
ON (default)
ON (default for wave quantities)
–
Phase
ON
ON
–
Real
ON
ON
ON
Imag
ON
ON
–
Unwrapped Phase
ON
ON
–
Screen elements
