User`s guide

Advanced Software Features 15
Agilent E5505A User’s Guide 345
Phase-Lock-Loop Suppression
Selecting “PLL Suppression Graph” on the View menu causes the software to
display the PLL Suppression Curve plot, as shown in Figure 272, when it is
verified during measurement calibration. The plot appears whether or not an
accuracy degradation occurs.
PLL suppression parameters
The following measurement parameters are displayed along with the PLL
Suppression Curve.
PLL gain change
This is the amount of gain change required to fit the Theoretical Loop
Suppression curve to the measured loop suppression. A PLL Gain Change of
greater than 1 dB creates an accuracy degradation (ACCY. DEGRADED) error.
If an accuracy degradation is detected, the amount of error is determined from
either the PLL Gain Change or the Maximum Error, which ever is larger. The
degradation itself is 1 dB less than the greater of these.
Figure 272 PLL suppression verification graph