N5465A Datasheet, PDF (7/11 Pages) Keysight Technologies – InfiniiSim Waveform Transformation

07 | Keysight | N5465A InfiniiSim Waveform Transformation Toolset for Infiniium Oscilloscopes - Data Sheet
Model your System as Detailed as you Need (Continued)
Measurement and simulation circuits
The core of the InfiniiSim waveform transformation software
is in defining two circuits: one that defines your measurement
setup and the other to define what you desire to have as your
measurement. The first we call the ‘measurement circuit’ and
the second is the ‘simulation circuit’. These can be as simple as
one block between the source and the oscilloscope load, or as
complex as nine circuit blocks as in general purpose model. The
simulation and measurement circuits share the topology selected,
however, in many cases, circuit definitions for each block will be
very different from measurement to simulation. This leads to great
flexibility in transforming acquisitions at a measurement point to
any other virtually probed location. For the circuit shown in Figure
6, for instance, Block `P’ has an S parameter file describing its
loading during measurement, however, for simulation, the loading
is desired to be eliminated, thus the `open’ designation.
Figure 6. Measurement and Simulation circuits. Blue designates the
measurement circuit elements while the brown labeling designates the
simulation circuit elements.
See what you deserve to see
With the InfiniiSim waveform transformation toolset, you can see
transformed signals in confidence whether channel elements are
being inserted removed or whether the measurement plane is
being relocated. Figure 7 shows a waveform of a digital signal at
1.8 Gb/s going through a combination of fixture and cable. Note
that for the longer sequences of identical digits the waveform
reaches a level that is very different from when the data changes
frequently. This is called ISI and is seen when the channel exhibits
low pass filter characteristics. The fixture and cables were
measured with a 4-port Vector Network Analyzer and removed
using the channel element removal selection in InfiniiSim. The
yellow CH1 trace in Figure 7 depicts the results. Note the blue
waveform depicting the ‘before measurement’ directly at the
transmitter versus the yellow waveform transformed using the
4-port channel model of the fixture.
Figure 7. De-embedded, yellow, channel 1 waveform along with original
channel 3 waveform.