Technical data

5-9
Operating Concepts
Sweep Types
Swept Edit Subsweep Menu
Using the EDIT, or ADD, softkey within the edit list menu will display the edit subsweep menu. This menu
lets you select measurement frequencies arbitrarily. Using this menu it is possible to define the exact
frequencies to be measured on a point-by-point basis at specific power levels and IF bandwidth settings.
The total sweep is defined with a list of subsweeps.
The frequency subsweeps, or segments, can be defined in any of the following terms:
• start/stop/number of points/power/IFBW
• start/stop/step/power/IFBW
• center/span/number of points/power/IFBW
• center/span/step/power/IFBW
See “Setting Segment Power” and “Setting Segment IF Bandwidth” on page 5-9 for information on how
to set the segment power and IF bandwidth.
The subsweeps may be entered in any particular order but they cannot overlap. The analyzer sorts the
segments automatically and lists them on the display in order of increasing start frequency, even if they are
entered in center/span format. The data is shown on the display as a single trace that is a composite of all
data taken. The trace may appear uneven because of the distribution of the data points, but the frequency
scale is linear across the total range.
Once the list frequencies have been defined or modified, the list frequency sweep mode can be selected
with the LIST FREQ [SWEPT], softkey in the sweep type menu. The frequency list parameters can also be
saved with an instrument state.
Setting Segment Power
To enable the SEGMENT POWER, function, you must first select LIST POWER ON off, in the edit
subsweep menu. List power is off by default and the asterisks that appear in the "power" column of the list
table indicate that power for the sweep is being set by the normal analyzer power controls.
The power settings for all segments are restricted to a single power range. This prevents the attenuator
from switching to different settings mid-sweep. Select the power range and then edit the list table to
specify the segment powers. If the power range is selected after the list has been defined, the list settings
may be affected.
When analyzer port power is uncoupled, the segment power level can be set independently for each port.
To do this, you must first select a measurement parameter to activate the port whose power you want to
set. For example, select S11 to set port 1 power, or S22 to set port 2 power. (Notice that the list mode table
will only display the currently selected port in the table. This is due to restricted display space.)
When analyzer port power is uncoupled, the LIST POWER ON off, softkey can also be set independently
for each port. For example, you may choose to set LIST POWER ON off, for forward measurements and
LIST POWER on OFF, for reverse measurements. In this case, the power would be set according to values
in the list when measuring the forward parameters. When measuring the reverse parameters, the power
would be set according to the normal analyzer power controls.
Setting Segment IF Bandwidth
To enable the SEGMENT IF BW, function, you must first select LIST IF BW ON off, in the edit subsweep
menu. List IF bandwidth is off by default and the asterisks that appear in the "IFBW" column of the list
table indicate that the IF bandwidth for the sweep is being set by the normal analyzer controls.
Narrow IF bandwidths require more data samples per point and thus slow down the measurement time.
Selectable IF bandwidths can increase the throughput of the measurement by allowing you to specify
narrow bandwidths only where needed.