U2021XA Datasheet, PDF (18/20 Pages) Keysight Technologies – U2020 X-Series USB Peak and Average Power Sensors

18 | Keysight | U2020 X-Series USB Peak and Average Power Sensors – Data Sheet
Graphical Example
A. System contribution to measurement uncertainty
versus power level (equates to step 6 result/2)
Note: The above graph is valid for conditions of free-run operation, with a
signal within the video bandwidth setting on the system. Humidity < 70 %.
B. Standard uncertainty of mismatch
Standard uncertainty of mismatch - 1 sigma (%)
0.5
0.45
SWR ρ
1.0
0.00
SWR ρ
1.8
0.29
0.4
1.05 0.02
1.90 0.31
1.10 0.05
2.00 0.33
0.35
1.15 0.07
2.10 0.35
0.3
1.20 0.09
2.20 0.38
0.25
1.25 0.11
2.30 0.39
1.30 0.13
2.40 0.41
0.2
1.35 0.15
2.50 0.43
0.15
1.40 0.17
2.60 0.44
0.1
1.45 0.18
2.70 0.46
0.05
0
0
1.5
0.20
2.80 0.47
1.6
0.23
2.90 0.49
0.1
0.2
0.3
0.4
0.5
1.7
0.26
3.00 0.50
ρ_DUT
Note: The above graph shows the Standard Uncertainty of Mismatch = ρ_DUT. ρ_Sensor /√2, rather than the Mismatch
Uncertainty Limits. This term assumes that both the Source and Load have uniform magnitude and uniform phase
probability distributions.
C. Combine A & B
U_C = √ (Value from Graph A)² + (Value from Graph B)²
Expanded uncertainty, k = 2, = U_C • 2 = . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
%