Keysight N9927-90001 User’s Guide 81
TDR (Time Domain Reflectometry) - Option 215
TDR Measurement Settings
An un-terminated cable (with NO perfect load at the end) will show faults that
appear to be beyond the end of the cable. These are NOT alias faults. These
faults appear as the signal reflects off the open at the end of the cable and
travels back down the cable toward the connection at the FieldFox.
Re-reflections are measured at the FieldFox as mirror images of the original
faults. The largest fault is the open end of the cable. To avoid confusion, set
the Stop distance shortly after that fault.
How to Prevent Undersampling
Undersampling is when the TDR measurement is inaccurate because the
frequency step size (resolution) is too large. The predominant symptom of this
is when the measured impedance is incorrect. For example, when measuring a
75
Ω
cable, a marker that is on a part of the trace without reflections shows
56
Ω
.
To prevent undersampling, set
TDR Sweep
to
Cable
. If undersampling still
occurs, set
TDR Sweep
to
Auto
. Then set
Auto Max Frequency
to a lower
value. Manually increase the Resolution so that the Start Frequency setting is
less than about 500 kHz.
Summary of Contents for N9913A
Page 6: ...6 ...
Page 106: ...106 Keysight N9927 90001 User s Guide NA Network Analyzer Mode NA Mode Settings ...
Page 202: ...202 Keysight N9927 90001 User s Guide SA Spectrum Analyzer Mode Channel Measurements ...
Page 444: ...444 Keysight N9927 90001 User s Guide Noise Figure Mode Option 356 CPU2 Only Troubleshooting ...
Page 470: ...Data Analysis Features All about Scale Settings 470 Keysight N9927 90001 User s Guide ...
Page 546: ...546 Keysight N9927 90001 User s Guide Connector Care Review ...
Page 548: ...548 Keysight N9927 90001 User s Guide Connector Care Review ...
Page 550: ...550 Keysight N9927 90001 User s Guide Specifications Data Sheet ...
Page 553: ...553 Keysight Handheld Analyzers N99xxA User s Guide D Korean Battery Safety Translation ...
Page 554: ...554 Keysight N9927 90001 User s Guide Korean Battery Safety Translation ...
Page 556: ...556 Keysight N9927 90001 User s Guide Keysight Software End User Licensing Agreement EULA ...
Page 557: ...Keysight N9927 90001 User s Guide 557 Keysight Software End User Licensing Agreement EULA ...
Page 558: ...558 Keysight N9927 90001 User s Guide Keysight Software End User Licensing Agreement EULA ...
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