Keysight N1913 User Manual page 146

3 Using E9300 E-Series Power Sensors
Accuracy
The value of –12 dBm lies in the lower range of the E-Series E9300 power sensor.
In autoranging mode ("AUTO"), the 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 power meter selects the low power
path in the 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
auto-averaging settings"
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
settings"
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.
146
on page 133.)
on page 133.) Manually lowering the filter settings speeds up the
"E9300 E-Series
"E9300 E-Series auto-averaging
Keysight N1913/1914A User's Guide