Trace Menu R&S
®
ZVA/ZVB/ZVT
1145.1084.12 4.40 E-6
It is possible to view the magnitude and phase of a complex quantity instead of the real and imaginary
p
art. The magnitude can be displayed on a linear scale or on a logarithmic scale. Both the real and
imaginary parts are displayed in the polar diagram.
Remote control:
CALCulate<Ch->Tr>:FORMat REAL
Imag
Selects a Cartesian diagram to display the imaginary part of a complex measured quantity.
Properties: The stimulus variable appears on the horizontal axis, scaled linearly. The imaginary part
Im(C) of the complex quantity C = Re(C) + j Im(C), appears on the vertical axis, also scaled linearly.
Application: The imaginary part of an impedance corresponds to its reactive portion. Positive
(negative) values represent inductive (capacitive) reactance.
Alternative Formats
It is possible to view the magnitude and phase of a complex quantity instead of the real and imaginary
part. The magnitude can be displayed on a linear scale or on a logarithmic scale. Both the real and
imaginary parts are displayed in the polar diagram.
Remote control:
CALCulate<Ch->Tr>:FORMat IMAGinary
Inverted Smith
Selects an inverted Smith chart to display a complex quantity, primarily a reflection S-parameter.
Properties: The Inverted Smith chart is a circular diagram obtained by mapping the positive complex
semi-plane into a unit circle. If the measured quantity is a complex reflection coefficient (S
11
, S
22
etc.),
then the unit Inverted Smith chart represents the normalized admittance. In contrast to the polar
diagram, the scaling of the diagram is not linear.
Application: Reflection measurements, see application example.
The axis for the sweep variable is lost in Smith charts but the marker functions easily provide the
stimulus value of any measurement point. dB values for the magnitude and other conversions can be
obtained by means of the Marker Format functions.
Remote control:
CALCulate<Ch-
Unwrapped Phase
Selects a Cartesian diagram with an arbitrarily scaled linear vertical axis to display the phase of the
measured quantity.
Properties: The stimulus variable appears on the horizontal axis, scaled linearly. The phase of the
complex quantity C, i.e. (C) = arctan ( Im(C) / Re(C) ), appears on the vertical axis. (C) is measured
relative to the phase at the start of the sweep (reference phase = 0°). In contrast to the normal Phase
format, the display range is not limited to values between –180° and +180°. This avoids artificial jumps
of the trace but can entail a relatively wide phase range if the sweep span is large.
Application: Phase measurements, e.g. phase distortion, deviation from linearity.
To Next Page
Loading...
