Limitless™
WDRR Receiver
Issue 1,
50063987
www.honeywell.com/limitless
24
Figure 8. Radiation Pattern of an Omni-directional Antenna
Toroid Radiation Pattern -
Pattern is 360 degrees in the vertical
plane, but not the horizontal plane
2.2 dBi RF Antenna Pattern -
Horizontal
2.2 dBi RF Antenna Pattern -
Vertical
The antenna radiates virtually zero power in the Z axis and most of the power in the X and Y axis. Increasing the
antenna’s gain will increase the power only in the X and Y axis. As a result, the radiation pattern becomes
narrower. For instance, this is analogous to the reflector in an automobile’s headlight. The reflector does not add
light or increase the luminous intensity of the light bulb, rather it simply directs all the light energy in the forward
direction where the light is needed most.
8.3
Antenna Mounting and Considerations
8.3.1
Antenna Mounting Location with Respect to RF Signal
WARNING
RF EXPOSURE
To satisfy FCC RF exposure requirements for mobile transmitting 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-located 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 corresponding WDRR monitor. 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 WDRR monitor, 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™ input and WDRR monitor 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.
