User's Manual

Broadcast Microwave Services, Inc. – 12367 Crosthwaite Circle – Poway, CA 92064 2
Phone: 800-669-9667, 1-858-391-3050 - Fax: 1-858-391-3049
Email: support@bms-inc.com Web: www.bms-inc.com
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 6 GHz Power Amplifier with maximum 4 Watt output power (OET Bulletin 65).
The 6 GHz Power Amplifier (PA) may ba a part of a non-broadcast transmitter and without an antenna it will not create
RF exposure (power density) exceeding the 1.0 mW/cm
2
FCC limit.
However a high-gain antenna such as a parabolic dish will greatly enhance the 6 GHz PA 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 6 GHz PA based on the formula mentioned in OET Bulletin 56.
The calculations have been done for different commonly used antenna in the BAS and Public Safety/ Law enforcement
applications.
Figure 1 shows the plot of the minimum exposure distance for 5dBi, 16dBi, and 30dBi antennas. The 6 GHz PA
transmits the maximum power of 4 Watt. 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. 1mW/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. The antenna used for this transmitter must not be co-located or operating in conjunction
with any other antenna or transmitter.