Agilent Technologies E4419B, User Manual

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2 Power Meter Operation
68 E4419B Power Meter User’s Guide
Setting Averaging
The power meter uses a digital filter to average power readings. The number of
readings averaged can range from 1 to 1024. This filter is used to reduce noise,
obtain the desired resolution and to reduce the jitter in the measurement
results. Increasing the value of the filter length reduces measurement noise.
However, the time to take the measurement is increased. You can select the
filter length or you can set the power meter to auto filter mode. The default is
“
AUTO
”.
When the auto filter mode is enabled, the power meter automatically sets the
number of readings averaged together to satisfy the filtering requirements for
most power measurements. The number of readings averaged together
depends on the resolution and the power level currently being measured.
Figure 2-10 lists the number of readings averaged for each range and
resolution when the power meter is in auto filter mode and is set to normal
speed mode (refer to the
Agilent EPM- 4418B/4419B Programming Guide
for
details of the readings averaged in the other speed modes).
Resolution is a window function and not a channel function. In the case where
a channel is set up in both the upper and lower window and the resolution
settings are different, the highest resolution setting is taken to calculate the
averaging number. For example, if the upper window has a resolution setting
of two and is measuring channel A - channel B and the lower window has a
resolution of four and is measuring channel A. In this instance, channel A
averaging is calculated with a resolution of four and channel B with a
resolution of two.