Product specifications

36
Improving stimulus power
level accuracy in pulse
profile measurements
In pulse profile measurements, regardless of wideband or narrowband detec-
tion techniques, receivers measure signals inside of pulses as well as noise
outside of pulses. If receiver leveling is used while the receivers measure noise,
the source tries to adjust the source power by referencing the noise measure-
ments causing source unleveled errors. Alternatively, the analyzer can remember
the previous receiver leveling during the stimulus on condition, and use it as
source power correction coefficients to improve the level accuracy. Receiver
leveling must be turned on once with the pulse modulators turned off. Follow
this procedure: turn off the pulse modulator, perform a calibration, switch to the
receiver leveling, select “Update source power calibration with leveling data”,
switch to the Open Loop leveling mode, then turn on the pulse modulator. Once
the receiver leveling result is used for source power cal (“Update source power
calibration with leveling data” can be found in the “Receiver Leveling” dialog
box shown in Figure 22), the pulsed stimulus level becomes reasonably accurate
in pulse profile measurements, as shown in Figure 27.
Figure 27. Narrowband pulse profile with “last receiver leveling result” used for
source power calibration