N2809A Datasheet, PDF (4/11 Pages) Keysight Technologies – Bandwidths up to 33 GHz

04 | Keysight | PrecisionProbe for Bandwidths up to 33 GHz - Data Sheet
Background – PrecisionProbe (continued)
Cables pose many of the same problems as probes with ca-
ble-to-cable variability. Oscilloscope vendors now mitigate
this problem with the use of de-embedding software (Key-
sight’s InfiniiSim N5465A software). Typically for cables,
you must characterize the cable using either a TDR or a
VNA. Both of these methods provide characterization and
s-parameters, but take time. It is the time required that typ-
ically will mean that you will characterize only one or two
cables, and use that characterization (s-parameter file) to do
the measurements of every similar cable they own, causing
cable-to-cable variability if the cables characteristics vary
from the “golden” cable.
PrecisionProbe
PrecisionProbe can solve the problems outlined in the back-
ground information by allowing quick characterization
of your entire probe system (including cables and switches).
Figure 4: Eye diagram with no correction, notice the minimized
eye margins due to fixture loss
The innovative software takes advantage of the fast “cal
output” signal on the 90000 Q-Series, 90000 X-Series, and
90000A Series oscilloscopes to properly characterize cables
and probes.
The software quickly (less than five minutes in most cases)
and accurately characterizes the desired element in the
system without adding more equipment. PrecisionProbe
– Characterizes probe input impedance
– Properly Creates Custom Probe Transfer Function
= VOut / VIn or VOut/VInc = VOut/VSrc
– Removes unwanted cable loss
Now every probe and cable in the system can have the
exact same response probe to probe or cable to cable,
without the inaccuraies that using one model can produce.
Custom probes can now be properly characterized and
unwanted responses can be removed.
Not only does PrecisionProbe characterize the cables, it
allows for immediate use on the same instrument. When
combining PrecisionProbe with the 90000 Q-Series, 90000
X-Series, and 90000A Series oscilloscopes one can char-
acterize their measuring system and be using it within
five minutes without adding more complicated, expensive
equipment. PrecisionProbe saves time and money while
increasing accuracy.
When combining Infiniimax probes with switches between
the amplifier and the probe head, PrecisionProbe allows
for full correction and automation of each probes path. Full
automation is then available to allow for quick swapping of
the inputs.
Figure 5: Same setup using PrecisionCable correction to compensate
for fixture loss