Keysight N9923A, Руководство пользователя, Страница: 97 / 276

Keysight N9923-90001 User’s Guide
97
DTF (Distance to Fault) Measurements
DTF Measurement Settings
The center frequency for the measurement is determined from the
calculated (Stop – Start) frequency values (seen on the second page of
DTF Settings):
The Loss value for the measurement is interpolated from the Freq/Loss pairs at
the Center Freq:
The correction for loss at 5 meters in one direction: 0.18 dB/m * 5m = 0.9 dB.
All DTF measurements correct for loss for travel down the DUT and back, so
double the correction: 0.9 dB * 2 = 1.8 dB.
Window Settings
Window settings provide the ability to choose between optimizing DTF
measurements for resolving closely-spaced faults or for the ability to measure
low-level faults.
How to select Window settings
— Press Meas Setup 4 .
— Then
Settings
.
— Then press arrows to move to the Window row.
— Then press
Edit
.
— Then press
Window
and choose from the following:
—
Maximum (Maximum – Optimized for dynamic range)
the noise floor
is lowered to provide the ability to measure low-level responses.
(Default setting)
—
Medium
– Compromise between Min and Max window settings.
—
Minimum
– Best Response Resolution, providing the ability to resolve
between two closely-spaced responses.
— Then press
Done Edi
t.
— Again press
Done
.
Calculated Start = 2.0 MHz
Calculated Stop = 3.598 GHz
Center Freq = 1.80 GHz
1 GHz = 0.1 dB/m
1.8 GHz = 0.18 dB/m
2 GHz = 0.2 dB/m