Atec Anritsu-S412D - Manual (Page 4)

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The LMR Master cable and antenna analyzer uses Frequency Domain Reflectometry (FDR) to help technicians and
wireless field engineers detect cable, feedline and antenna system problems before they become costly, time-consuming
system failures. Superior immunity to ambient RF levels, and excellent directivity and source match ensure accurate and
repeatable measurements.
FDR Technique
Frequency Domain Reflectometry (FDR) and Time Domain Reflectometry (TDR) have similar acronyms, and both
techniques are used to test transmission lines. But, that’s where the similarities end. TDRs are not sensitive to RF problems:
the TDR stimulus is a DC pulse, not RF. Thus, TDRs are unable to detect system faults that often lead to system failures.
Additionally, FDR techniques save costly, time-consuming trouble shooting efforts by testing cable feedline and antenna
systems at their proper operating frequency.
Deficient connectors, lightning arrestors, cables, jumpers or antennas can be replaced before call quality is compromised.
Quick, Simple Measurements
LMR Master performs various RF measurements aimed at simplifying cable feedline and antenna system analysis: Return
Loss, SWR, Cable Loss and Distance-to-Fault (DTF). A single softkey selection on the main menu activates the desired
measurement mode.
Distance-to-Fault
Although a Return Loss test can show users the magnitude of signal
reflections, it can not show the precise location of a fault within the cable
and antenna system. Distance-To-Fault measurements provide the clearest
indication of trouble areas as it shows both the magnitude of the signal
reflection and the location of the signal anomaly.
Distance-To-Fault can easily identify connector transitions, jumpers and
kinks in the cable and antenna system. Return Loss/SWR measurement data
is processed using Fast Fourier Transform and the resulting data indicates
Return Loss/SWR versus distance.
Cable Loss
Cable Loss measures the RF energy that is lost to heat and leakage as
the signal travels down the cable. Insertion loss can be verified prior to
deployment, when you have access to both ends of the cable, or on installed
cables with access to the opposite end.
The S412D LMR Master automatically calculates and displays the average
cable loss so there’s no more guess work or need for complicated calculations
in the field.
Return Loss, SWR
Return Loss measures the signal energy that is “reflected” or returned back
to where it came from. VSWR (Voltage Standing Wave Ratio) is another
method to measure the reflections. Return Loss and SWR “system”
measurements ensure conformance to system performance engineering
specifications. Measurements can easily be toggled between the two modes
and can be performed without climbing the tower.
Cable and Antenna Analysis – Increase
System Uptime