User's Manual

Electrostatic Discharge (ESD) Nexus FT Strand Mount
viii 044-05320 Rev A
Human Exposure to RF Radiation
Safe distances must be kept when working around antennas. The following paragraphs describe the cautions
to be aware of during the installation and maintenance of antenna systems and how to calculate safety
distances needed for RF radiation at different antenna power and frequencies.
Antennas
To be able to receive and transmit signals, a Nexus FT RM ORD is connected to a donor antenna directed
towards the base station and a service antenna directed towards the coverage area. A fiber optic cable from the
base station might, however, be substituted for the donor antenna.
Installation and Maintenance of Antenna Systems
Installation and maintenance of all antenna systems must be performed with respect to the radiation exposure
limits for public areas. The antenna radiation level is affected by Nexus FT RM ORD output power, antenna
gain, and transmission devices such as cables, connectors, splitters and feeders. Also have in mind the system
minimum coupling loss, typically between 25dB and 35dB, is determined by a standard with the purpose to
protect base stations from noise and other performance dropping effects.
Radiation Exposure
The World Health Organization (WHO) and International Commission on Non-Ionising Radiation Protection
(ICNIRP) have determined recommendations for radiation exposure. ICNIRP recommends not to exceed the
following radiation power for public exposure:
Frequency Radiation power
800/900 MHz 4.5W/m²
1800/1900 MHz 9.0W/m²
2100 MHz 10.0W/m²
For antennas larger than 20cm the maximum radiation power can be calculated by using the following formula:
Electrostatic Discharge (ESD)
ESD can severly damage essential parts of the equipment if not handled carefully. Parts on
printed circuit board assemblies (PCBA) as well as other parts in the equipment are sensitive
to ESD. Never touch the PCBA or uninsulated conductor surfaces unless absolutely
necessary.
If you must handle the PCBAs or uninsulated conductor surfaces, use ESD protective
equipment or first touch the chassis with your hand. Never let your clothes touch PCBAs or
uninsulated conductor surfaces and always store PCBAs in ESD-safe bags.
S= P/(4
πr
2
)
S = Radiation power in W/m²
P = Output power in W
r = Distance between antenna and human in meters
DRAFT