GUI Reference
R&S
®
ZNC
137
User Manual 1173.9557.02 ─ 13
Application:
Phase measurements, e.g. phase distortion, deviation from linearity.
Tip (alternative formats):
The magnitude of each complex quantity can be displayed on
a linear scale or on a logarithmic scale. It is possible to view the real and imaginary parts
instead of the magnitude and phase. Both the magnitude and phase are displayed in the
polar diagram. As an alternative to direct phase measurements, the analyzer provides
the derivative of the phase response for a frequency sweep (Delay).
Remote command:
PHASe
Smith
Selects a Smith chart to display a complex quantity, primarily a reflection S-parameter.
Properties:
The Smith chart is a circular diagram obtained by mapping the positive com-
plex semi-plane into a unit circle. Points with the same resistance are located on circles,
points with the same reactance produce arcs. If the measured quantity is a complex
reflection coefficient (S
11
, S
22
etc.), then the unit Smith chart represents the normalized
impedance. In contrast to the polar diagram, the scaling of the diagram is not linear.
Application:
Reflection measurements; see example in
chapter 3.2.4.4, "Smith Chart"
Tip:
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 command:
SMITh
Polar
Selects a polar diagram to display a complex quantity, primarily an S-parameter or ratio.
Properties:
The polar diagram shows the measured data (response values) in the com-
plex plane with a horizontal real axis and a vertical imaginary axis. The magnitude of a
complex value is determined by its distance from the center, its phase is given by the
angle from the positive horizontal axis. In contrast to the Smith chart, the scaling of the
axes is linear.
Application:
Reflection or transmission measurements, see example in
Tip:
The axis for the sweep variable is lost in polar diagrams 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 command:
POLar
Delay
Calculates the (group) delay from the measured quantity (primarily: from a transmission
S-parameter) and displays it in a Cartesian diagram.
Properties:
The group delay τ
g
represents the propagation time of wave through a
device. τ
g
is a real quantity and is calculated as the negative of the derivative of its phase
response. A non-dispersive DUT shows a linear phase response, which produces a con-
stant delay (a constant ratio of phase difference to frequency difference).
Trace Settings
