HP 8753E To Divide Measurement Data by the Memory Trace, ‘RI Ratio Measurements in Channel 1

To Divide Measurement Data by the Memory Trace

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.
il... .:	i.i	.:..

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

2. press (jj ~~~ar~~~~, to subtract the memory from the measurement data.

;;;;A.::....::.....,...:.... ...2..

The analyzer performs a vector subtraction on the complex data.

‘RI Ratio Measurements in Channel 1 and 2

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.
,,.,.,....;.,.,,.,.,.,.,.....,.,..,.;	to mcouple the c.,annels.
1. Press lMenJ ~~~~~~~~~~~~
..i.................:: .: i.:::........;.;~ i.......... .::: i.......i .A..

2.Make sure that both channels must have the same number of points.

a. press (~, [=, ~~~~~~~~~~ and notice the number of points setting, shown

on the analyzer display.

.... ..I.............................,.,.,..: .,.,p,.,,,,.‘I .& ...:.,:::::~ .... ..:::.: ....:,:,:,:-;,:::::.:

b. Press @iZZ) [Menu_) ~~~~~~~~~:~~~~~ and enter the same value that you observed for

. .,,a. ........ i ,.......::::.:...A.................~~~.~~.......:,.;.;.,;;;..;;;.i ...... .::::::

the channel 1 setting.

3. Press ~~isp,ay, ~~~ ~~~~~~~,~~~~ to ratio channels l and 2, and put the results in the

,.;;........ ;;:.A....LL.;. ;.....1....AT.T ...._.... ............L...~~~~,~... ...,..,~~~ .............i

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.

2-8 Making Measurements