Atec Anritsu-VNA Series - Manual (Page 5)

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These uncertainty curves show how frequency range, DUT Match, and cable loss impact worst-case uncertainty of round-trip cable loss measurements. The uncertainty curves,
separated by frequency range, are shown for DUT Match cable loss conditions of -20 dB, -25 dB, and -30 dB. For DUT Match of 30 dB and cable loss of 4 dB to 5 dB (reflection
measurement of 8 dB to 10 dB) the worst-case uncertainties are approximately ± 1 dB.
Uncertainty Curves for Round-Trip Cable Loss Measurements (1-Port)
Round-trip cable loss measurements are convenient for field personnel testing installed cable or waveguide runs. This one-port
technique provides one-way data after twice traversing the cable. The following two sets of uncertainty curves, less than 6 GHz
on the left and greater than 6 GHz on the right, present worst-case uncertainty by DUT Match (i.e., Log Mag) when using
VNA Master for one-port cable loss measurements. As a practical tip, consider using a two-port transmission measurement
technique to improve upon these one-port cable loss uncertainties.
VNA Master (MS20xxC), 5 kHz - 6 GHz
One Port Cable Loss (Log Mag / 2) Uncertainty vs. DUT Match
0.1
1
10
Uncertainty (dB)
0 2 4 6 8 10
Cable Loss, Log Mag / 2 (dB)
-20 dB
-25 dB
-30 dB
VNA Master (MS20xxC), 6 GHz - 20 GHz
One Port Cable Loss (Log Mag / 2) Uncertainty vs. DUT Match
-20 dB
-25 dB
-30 dB
0.1
1
10
Uncertainty (dB)
0 2 4 6 8 10
Cable Loss, Log Mag / 2 (dB)