Concepts and Features
R&S
®
ZNB/ZNBT
102
User Manual 1173.9163.02 ─ 38
4.2.3 Trace Formats
A trace format defines how a trace is represented in a diagram.
The R&S
ZNB/ZNBT supports the following trace formats:
●
"dB Mag" , "Phase" , "SWR" , "Unwr Phase" , "Lin Mag" ,
"Real" , "Imag" and "Delay" .
●
Complex trace formats "Polar" , "Smith" and "Inv Smith"
The VNA firmware allows arbitrary combinations of trace formats and measured quan-
tities. However, in order to extract useful information from the measured data, it is
important to select a trace format which is appropriate for the analysis of a particular
measured quantity; see
Chapter 4.2.3.3, "Measured Quantities and Trace Formats"
4.2.3.1
Cartesian Trace Formats
Cartesian trace formats assign a scalar response to the stimulus value (frequency,
power, or time). The response may be calculated from the measured quantity at the
related stimulus value, but it can also be the result of some mathematical transforma-
tion of the original (unformatted) trace.
Diagram Representation
When a Cartesian trace is assigned to a diagram, the stimulus variable appears on the
horizontal axis (x-axis), the response values appear on the vertical axis (y-axis).
Graph Scaling
●
The y-axis scale is always linear (although the y-axis values may be obtained from
the measured data by non-linear conversions).
●
The x-axis scaling depends on the sweep type of the channel to which the trace is
assigned:
–
For sweep types "Lin Freq", "Power", "CW Mode" and "Time" it is scaled line-
arly.
–
For sweep type "Log Freq" it is scaled logarithmically.
The resulting linear or lin-log grid is plotted with the formatted trace.
The following examples show "dB Mag" Cartesian traces for the same measured quan-
tity and sweep range, but with "Lin Freq" and "Log Freq" sweep types.
Screen Elements
