Keysight Technologies N7020A, Руководство пользователя

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Using the Power Rail Probe
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N7020A and N7024A Power Rail Probes User’s Guide 43
To achieve the best signal fidelity, it is vital that the physical connection and
ground impedance of the probe be minimized. Any unnecessary length in either
the probe's signal or ground can potentially cause capacitive coupling and
inductive pick-up larger than the signal of interest. These probes support three
connection methods, well-suited for high fidelity measurements:
• The N7022A main cable, connected directly to an SMA port on the DUT,
provides the highest fidelity since the ground and signal are intimately mated
with an SMA connector. Connectors other than SMA such as SMB and SMC
can be used with an appropriate adapter. The adapters are not supplied with
the probe.
• The N7021A is a prepared coaxial-cable pigtail that allows the probe to be
soldered to the DUT. It is recommended that the coaxial shield be soldered
directly to ground, thus minimizing the ground impedance.
• The N7032A browser or N7033A browser with hand-held probing.
As with any single-ended probe, there may be a concern of creating a ground loop
by the connection of the DUT ground to the probe/scope ground. This generally
does not cause a measurement issue as long as the DUT ground is not radically
different than the scope ground. You can test this by connecting the probe’s
ground and signal contacts to the DUT ground. You should not see any significant
signal on the oscilloscope’s screen.