Jackson Labs PHASE STATION 53100A, User Manual

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PhaseStation 53100A User’s Manual V1.04 25-Apr-2022 135
Measure three independent DUTs (three-
cornered hat)
This measurement role is similar to
Measure single DUT with dual external references,
in that it is
capable of performing a cross-correlated phase noise and/or AM noise measurement of a single device
under test that is connected to channels 3 and 4 via an internal or external RF splitter. The phase noise
and AM noise contributions from the two independent references connected to channels 1 and 2 –
whether internal or external – will be averaged out of the measurement over time.
However, three stability plots are generated in this measurement role rather than only one. In these
stability plots, unlike the AM and phase noise measurements, the three connected devices are treated
as individual test sources. Each source is represented as a DUT in one of the plots, and each also serves
as a reference in one of the plots. The resulting trio of mutually-dependent stability plots can be
rendered by TimeLab In the usual fashion, appearing as three independent traces, or they can be
rendered in a special display mode using the
Trace → Show separated xDEV variances (N-cornered hat)
(Ctrl-h)
function (Page 97.) In this mode, TimeLab will attempt to display the stability characteristics of
each device by itself, rather than showing traditional stability measurements based on two contributing
sources.
Note that any phase noise/AM noise data
obtained in this measurement role will be
associated only with the first of the three
stability plots. The remaining two plots will not
contain any noise data.
As with the other dual-reference measurements,
please refer to
Application Note 53100A-2 for a
discussion of three-cornered hat measurements
in TimeLab with detailed examples.
Figure 61: Three-cornered hat display