Step Control Slave
Function Group
FREQUENCY
M e n u M a p
Description
This
lets you designate the swept CW generator as the slave
in a dual swept CW generator measurement system. A dual swept
CW generator system (two-tone measurement system) facilitates
accurate device characterizations by providing one
reference
for both sources.
Figure S-l shows the connections required for a two-tone system. On
the message line, the status message
EXT REF
appears indicating the
swept CW generator has an external
reference. The start
and stop frequencies of the slave can be offset above or below those
set on the master for fixed offset two-tone measurements.
To synchronize properly for swept offset measurements, the 0 to 10
volt sweep ramp must be actively sweeping on the slave. If a CW
frequency is selected as the fixed LO frequency, the sweep ramp is
deactivated and the proper synchronization does not occur. Select a
center frequency with zero span to keep the slave’s voltage sweep
ramp active and ensure proper synchronization.
For synthesized step sweep measurements, set the number of
sweep points on the slave the same as on the master swept CW
generator. If the master swept CW generator is connected to a
network analyzer, the analyzer automatically sets the master
swept CW generator’s step size to match the number of points
displayed on the analyzer. Since the slave swept CW generator is not
connected to the analyzer, set the slave to match the master swept
CW generator. Allow the master to trigger the slave’s steps; set
Step
Pt Trig Ext on the slave swept CW generator.
For ramp sweep measurements, on the slave set the sweep time
equivalent to the master swept CW generator. If the master is
connected to a network analyzer, the slave’s sweep time is slightly
longer than the master’s because the analyzer does not stop the
sweep precisely on the last point. Use the following formula to
determine the slave’s sweep time for a system controlled by an
analyzer.
x
1.03 =
For fixed-offset ramp sweep measurements, the same sweep time must
be set on both the master and the slave. Since the master’s sweep
time is typically determined by the measurement configuration, set
the slave to match the master.
For more accurate ramp sweeps, select
Span Cal. Always on
both the master and slave swept CW generators. When this feature
S-56 Operating and Programming Reference
