Agilent Technologies FieldFox N9913A User Manual page 163

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.
Use Data - Memory to show the relative differences between two signals. Use for
comparison of very small signals, such as the S11 match of two connectors.
In the following table, Data/Mem shows both pairs of connectors to have the
same 2 dB difference. However, the second pair of connectors have much better
S11 performance (–50 and –52) and the relative significance is shown in the
Data-Mem values.
Data Analysis Features
Values to compare
0.5 dB and 0.6 dB
0.5 dB and 0.7 dB
Values to compare
–10 dB and –12 dB
–50 dB and –52 dB
Data/Mem Data-Mem
0.1 dB –39 dB
0.2 dB –33 dB
Data/Mem Data-Mem
2 dB –24 dB
2 dB –64 dB
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