ETS-Lindgren 3161 Octave Horn Antenna - Manual (Page 28)

Conversion Formulas
Following are some useful conversion formulas, including how the constants are
obtained:
E QUATION 1
dBm=dB( μV)-107
The power is related to the voltage and the system impedance as:
P
V
R
=
2
In a 50 Ω system, the previous equation becomes:
10 20 10 50
10 10 10
log log log ( ) P V
= −
Converting from dB to dBm for power and from dB(V) to dB( µ V) for
voltage, the overall constant becomes:
30 120 10 50 107
10
− − = − log ( )
28 | Radiated Emissions Measurements