About Math Operations - Agilent Technologies N9913A User Manual

How to display data and memory traces
 Press Trace
 Then
How to perform Trace Math
Trace math is performed between a live trace and a memory trace. When one of
the following math operations are selected, the yellow data trace displays the
current measurement with the selected trace math applied. The math operation
symbol indicated below in [brackets] is displayed on the lower left corner of the
screen.
 Press Trace 6 .
 If not already stored, press
 Then
 Then choose one of the following:

About Math Operations

Data / Memory and Data - Memory math operations are performed on complex
linear data before it is formatted. Because data is often viewed in log format, it is
not always clear which of the two math operations should be used. Remember:
dividing linear data is the same as subtracting logarithmic data. The following
illustrates, in general, when to use each operation.
Use Data / Memory for normalization purposes, such as when comparing traces
"before" and "after" a change is made or when measuring trace noise. In the
following table, the Data/Mem values intuitively show the differences between
traces. It is not obvious what Data-Mem is displaying.
188
6 .
Data->Mem to store the current live trace into memory. A 'beep' sounds
to confirm the data trace has been saved to memory. There is no display
annotation that indicates that the memory trace has been stored.
Press Data to view only the data trace.
o
Press to view only the memory trace.
Memory
o
Press
Data & Memory
o
trace.
memory.
Data Math.
Data + Memory [D+M] Current measurement data is added to the data in
o
memory.
Data – Memory
[D-M] Current measurement data is subtracted from the
o
data in memory.
Data / Memory [D/M] Current measurement data is divided by the data in
o
memory.
Math Off [Data] Displays trace data with NO math applied.
o
Values to compare
0.5 dB and 0.6 dB
0.5 dB and 0.7 dB
to view both the live trace and the stored memory
to store the current live trace into
Data->Mem
Data/Mem
0.1 dB
0.2 dB
Data-Mem
–39 dB
–33 dB
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