User's Manual

ii
WARNING!
RF RADIATION EXPOSURE HAZARD
This warning is provided by Broadcast Microwave Services (BMS) Inc. for safety purpose. The
following information help to reduce the risk of RF exposure hazard.
FCC Limit of RF Exposure
According to Federal Communication Commission (FCC), the Maximum Permissible Exposure (MPE) for
FR radiation has been set to 1.0 mW/cm
2
for the Field-Coder II equipment (OET Bulletin 65).
The Field-Coder II with Power Amplifier is a non-broadcast transmitter and without an antenna it will not
create RF exposure (power density) exceeding the 1.0 W/cm
2
FCC limit.
However a high-gain antenna such as a parabolic dish will greatly enhance the Field-Coder II output power
density beyond the MPE limit of 1.0 mW/cm
2
.
In this situation a minimum distance from the antenna needs to be calculated in order to keep the MPE
always below the safety limit. The calculation has been done for Field-Coder II based on the formula
mentioned in OET Bulletin 56.
The calculations have been done for different commonly used antenna in Electronic New Gathering (ENG)
systems.
Digital Transmission
Figure 1 shows the plot of the minimum exposure distance for 0dBi, 5dBi, 16dBi, and 30dBi antennas. The
2 GHz Field-Coder II with Power Amp transmits the maximum power of 5 Watts. The minimum exposure
distances are found from the cross points of the exposure graphs (for various antennas) with the line of
maximum permissible exposure (i.e. 1 W/cm
2
). Notice that the numbers in Figure 1 predict the worse case
scenario, which is straight in front of the antenna (exposing to the antenna main-lobe). Obviously the side-
lobe exposures are well below these numbers as the radiation intensity dramatically reduces on the side
lobes.