Setting Averaging; Averaged Readings - Agilent Technologies E4418B User Manual

Power Meter Operation

Setting Averaging

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 2-9 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 E4418B/E4419B 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 2 and is measuring channel
A and the lower window has a resolution of 4 and is also measuring channel A. In this
instance channel A averaging is calculated with a resolution of 4.
Minimum Sensor Power
10 dB
10 dB
10 dB
10 dB
Maximum Sensor Power
These four resolution levels represent:
2-38
Figure 2-9: Averaged Readings
1
1
1
1
1
1
Resolution Setting
2 3 4
8 128 128
1 16 256
1 2 32
1 1 16
1 1 8
Agilent E4418B User's Guide