Agilent Technologies U2000 Series, Руководство по эксплуатации и обслуживанию

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Operating Information 2
U2000 Series Operating and Service Guide 29
measurement of this signal. However, range holding in “UPPER” (the high
power path), for a more accurate measurement, results in a considerably
increased number of filtering processes.
Speed and Averaging
The same signal also requires a specific consideration of the measurement
speed. As shown above, in auto- ranging mode, the U2000/1/4A sensor
determines the average power level is below
– 7 dBm and selects the low
power path. With auto- averaging configured, minimal filtering is applied.
Values of one to four for average power levels above –20 dBm are used in
the low power path. (Refer to
“Auto- averaging settings” on page 26.)
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 one to 128 for
average power levels less than –7 dBm are used. (Again, refer to
“Auto- averaging settings” on page 26.) Manually lowering the filter settings
speeds up the measurement but can result in an unwanted level of jitter.
Summary
Attention must be paid to signals where the average power levels are in
the low power path range while the peaks are in the high power path
range. You can achieve best accuracy by selecting the high power path or
achieve best speed by selecting the low power path.