Table A-43 Unit Conversion Formula - Keysight U8903B User Manual

The units can be computed using the following formulas.
Table A-43 Unit conversion formula
Unit Formula
f – f
ΔHz
ref
20 × log
dB
(ratio) – R
ΔdB
dBg
20 log 10 ×
dBm
10 log 10 ×
dBr
20 log 10
×
dBu
20 log 10
×
20 × log
dBv
V
------- -
W
Z ref
V – V
ΔV
ref
V
------- -
V
ref
or
x
Ratio (in %)
---------------------- -
R ref (in %)
% 100 × (ratio)
[a] When the Vrms measurement unit is changed to Watt or dBm, the reference impedance setting will be used for the power level calculation. The
reference impedance refers to the circuitry impedance or load impedance connected to the analyzer when calculating power level. Note that in a
loopback test with no load impedance, the measured voltage value will be twice the expected value as there is no voltage divider present. This will
return a power measurement greater than 6.02 dB if a load is present.
[b] Reference level is defined as a user-entered or a captured value from the current reading as a relative level for the subsequent measurement
reading. It can be set to delta, linear, or log scale.
Keysight U8903B User's Guide
(ratio)
10
ref
2
⎛ ⎞
V rms
⎜ ⎟
------------- -
⎜ ⎟
V gen
⎝ ⎠
2
⎛ ⎞
1000
V rms
⎜ ⎟
-------------------------- -
⎜ ⎟
Z ref
⎝ ⎠
2
⎛ ⎞
V rms
⎜ ⎟
------------- -
⎜ ⎟
V
ref
⎝ ⎠
V rms
⎛ ⎞
---------- -
⎜ ⎟
⎝ 0.6 ⎠
(V )
10 rms
Description
f = Reference frequency
ref
-
R = Reference ratio
ref
V = Amplitude of the generator signal for a corresponding channel
gen
Z = Reference impedance
ref
V = Reference level
ref
-
-
[a]
Z = Reference impedance
ref
[b]
V = Reference level
ref
[b]
V = Reference level
ref
R = Reference ratio
ref
-
Appendixes A
557