Certificate Of Compliance

HBCS Report # FCC_12003 Page 10 of 17
Emissions Tests Calculations
In the case of indoor measurements, radiated emissions measurements are made by the
manipulation of correction factors using Rohde and Schwarz ES-K1 software. This is done
automatically by the software during the final measurement process.
In both cases, the level of the Field Strength of the interfering signal is calculated by adding the
Antenna Factor, Cable Factor and by subtracting the Amplifier Gain from the measured reading.
The basic equation is as follows:
FS = RA + AF + (CF –AG)
Where: FS = Field Strength
RA = Receiver (indicated) Amplitude
AF = Antenna Factor
CF = Cable Attenuation Factor
AG = Amplifier Gain
This laboratory uses an approach of combining the CF and AG using an end-to-end measurement
of the entire cabling system, including the test cable, any in-line amplifiers, attenuators, or
transient protection networks, all measured in-situ.
For a sample calculation, assume a receiver reading of 52.5 dBuV is obtained. With an antenna
factor of 7.4 and a combined cable factor (CF + AG) of -27.9:
FS = 52.5 + 7.4 + (-27.9) = 32 dBuV/m
FS = 32 dBuV/m
If desired, this can be converted into its corresponding level in uV/m:
FS = 10^((32 dBuV/m)/20) = 39.8 uV/m