Sensing and Internet of Things
27
Installation and Technical Manual for the
Limitless™ Multi-Protocol Receiver, WMPR Series
ISSUE B
32309669
8.3 | Antenna Mounting and Considerations
8.3.1 Antenna Mounting Location with Re-
spect to RF Signal
m
WARNING
RF EXPOSURE
To satisfy FCC RF exposure requirements for mobile transmit-
ting devices, a separation distance of 20 cm [7.87 in] or more
should be maintained between the antenna of this device
and persons during device operation. To ensure compliance,
operation at closer than this distance is not recommended.
The antenna used for this transmission must not be co-locat-
ed in conjunction with any other antenna or transmitter.
Failure to comply with these instructions could result in
death or serious injury.
There are several environmental factors to consider when
determining antenna location during installation. These factors
can affect the radio frequency (RF) signal strength being both
transmitted and received by the Limitless™ input and corre-
sponding WMPR. It is desirable for the antenna to be mounted
in a place that will limit exposure of adjacent materials/objects
between the Limitless™ switch and WMPR, as they have an
effect on RF signal strength. If the mounting location for an
omni-directional antenna is on the side of a building or tower,
the antenna pattern will be degraded on the building or tower
side.
Obstacles that affect antenna patterns and RF signal strength:
•
Indoor: Concrete, wood, drywall, metal walls, etc.
•
Outdoor: Vehicles, buildings, trees, structures, topology,
weather conditions, chain link fence, major power cables,
etc.
The best performance is achieved when both the Limitless™ in-
put and WMPR antennas are mounted at the same height and
in a direct line of sight (LOS) with no obstructions. Generally,
the higher the antenna is above ground, the better it performs.
Another concern is RF interference, discussed in Section 8.4.3.
Figure 46. Limitless™ Input to WMPR with RF Signal
Line of Sight (LOS) Free From Obstacles
Figure 47. Limitless™ Input to WMPR with RF Signal
Line of Sight (LOS) Affected by Obstacles