Accuracy; Speed And Averaging; Summary - Keysight Technologies E Series Operating And Service Manual

Accuracy

The value of –12 dBm lies in the lower range of the Keysight E-Series E9300
power sensor. In autoranging mode ("AUTO") the Keysight EPM Series power
meter determines the average power level is below –10 dBm and selects the low
power path. However, the peak amplitude of –6 dBm is beyond the specified,
square law response range of the low power path diodes.The high power path
(–10 dBm to +20 dBm) should be used to ensure a more accurate measurement of
this signal. However, range holding in "UPPER" (the high power path), for a more
accurate measurement, results in considerably more filtering.

Speed and averaging

The same signal also requires that consideration is given to measurement speed.
As shown above, in autoranging mode the Keysight EPM series power meter
selects the low power path in the Keysight E-Series E9300 power sensor. With
auto-averaging also configured, minimal filtering is applied. Values of 1 to 4 for
average power levels above –20 dBm are used in the low power path. (Refer to
Figure
If the range is held in "UPPER" for more accuracy, the measurement is slower.
More filtering is applied due to the increase in noise susceptibility at the less
sensitive area of the high power path. Values of 1 to 128 for average power levels
less than –10 dBm are used. (Again, refer to
filter settings speeds up the measurement but can result in an unwanted level of
jitter.

Summary

Attention must be paid to signals whose average power levels are in the low
power path range whilst their peaks are in the high power path range. You can
achieve best accuracy by selecting the high power path or best speed by selecting
the low power path.
Keysight E-Series E9300 Operating and Service Guide
2-1.)
Making Measurements
Figure 2-1.) Manually lowering the
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