Jackson Labs PHASE STATION 53100A, User Manual

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PhaseStation 53100A User’s Manual V1.04 25-Apr-2022 39
A brief architectural note
It can be helpful to understand some basic details about the 53100A’s DSP topology, especially when
measurements may be constrained by available memory and CPU resources. A key observation is that
the two basic measurement categories corresponding to the
Measure stability and Measure phase
noise / Measure AM noise options in the TimeLab acquisition dialog use completely separate data
records and internal processing pipelines.
The “phase record” mentioned in the documentation and help text has nothing to do with Phase noise
measurements, for example. Instead, the phase record is a block of low-bandwidth phase difference
samples from a single DUT/reference channel pair. It is used only for
Stability measurements, which
include ADEV, MDEV, TDEV, HDEV, and MTIE as well as the frequency- and phase-difference plots.
The diagram above represents a more detailed view of the right half of the block diagram from the
preceding section. While TimeLab allows phase records from multiple channel pairs to be recorded
during a single measurement, the most common measurements yield a single phase record created
from two parallel streams of complex data samples arriving from one DUT input channel (
Q3,I3 ) and one
reference input channel ( Q1,I1 ). (Channels 2 and 4 do not participate in single-DUT stability
measurements by default unless the cross ADEV stability measurement role is selected.) The two
streams from channels 1 and 3 are decimated to accommodate the requested measurement bandwidth
(ENBW) – typically 5 Hz to 500 Hz, with rates up to 50 kHz supported through the use of additional
decimation. The phase differences between corresponding samples in the two decimated streams are
Figure 7: Digital processing pipeline