HP 8753E User Manual page 59

You can use this feature for ratio comparison of two traces, for example, measurements of gain
or attenuation.
1. You must have already stored a data trace to the active channel memory, as described in "To
Save a Data Trace to the Display Memory."
2. Press (Display) ~~~~~~ to divide the data by the memory.
The analyzer normalizes the data to the memory, and shows the results
To Subtract the Memory Trace from the Measurement Data Trace
You can use this feature for storing a measured vector error, for example, directivity. Then,
you can later subtract it from the device measurement.
1. You must have already stored a data trace to the active channel memory, as described in "'lb
Save a Data Trace to the Display Memory. ff
The analyzer performs a vector subtraction on the complex data.
You may want to use this feature when making amplifier measurements to produce a trace that
represents gain compression. For example, with the channels uncoupled, you can increase the
power for channel 2 while channel 1 remains unchanged. This will allow you to observe the
gain compression on channel 2.
2. Make sure that both channels must have the same number of points.
on the analyzer display.
b. Press @iZZ) [Menu_) ~~~~~~~~~:~~~~~ and enter the same value that you observed for
the channel 1 setting.
channel 2 data array. This ratio is applied to the complex data.
4. Refer to Chapter "Measuring Gain Compression" for the procedure on identifying the 1 dB
compression point.
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