ProSoft Technology RLX2-IFH9E - Manual (Page 58)

Antenna Reference RLX2-IFHxE ♦ Industrial Wireless
User Manual Industrial Frequency Hopping Ethernet Radios
Page 58 of 81 ProSoft Technology, Inc.
May 28, 2014
 If radio antennas are on the same network, mount them so they have the
same polarity. If the antennas are on separate networks, mount them so they
have a different antenna polarity
—for example, mount transmitting and
receiving antennas for one network vertically, and those for the other network
horizontally.
 Space radios at least three feet (one meter) apart so they do not overload
each other. If antennas must be near each other:
o Mount omnidirectional antennas directly above each other.
o Position directional antennas so they do not point at nearby antennas.
Place antennas side by side if they point in the same direction. Place
antennas back to back if they point in opposite directions.
4.1.2 Antenna Pattern
Information between two wireless devices is transferred by electromagnetic
energy radiated by one antenna and received by another. The radiated power of
most antennas is not uniform in all directions and has varying intensities. The
radiated power in various directions is called the pattern of the antenna. Mount
each antenna so that its direction of strongest radiation intensity points toward
the other antenna or antennas with which it will exchange signals.
Complete antenna patterns are three-dimensional, although often only a two-
dimensional slice of the pattern is shown when all the antennas of interest are
located in roughly the same horizontal plane, along the ground rather than above
or below one another.
A slice taken in a horizontal plane through the center (or looking down on the
pattern) is called the azimuth pattern. A view from the side reveals a vertical
plane slice called the elevation pattern.
An antenna pattern with equal or nearly equal intensity in all directions is
omnidirectional. In two dimensions, an omnidirectional pattern appears as a
circle (in three dimensions, an omnidirectional antenna pattern would be a
sphere, but no antenna has a true omnidirectional pattern in three dimensions).
An antenna is considered omnidirectional if one of its two dimensional patterns,
either azimuth or elevation pattern, is omnidirectional.
Beamwidth is an angular measurement of how strongly the power is
concentrated in a particular direction. Beamwidth is a three dimensional quantity
but can be broken into two-dimensional slices just like the antenna pattern. The
beamwidth of an omnidirectional pattern is 360 degrees because the power is
equal in all directions.
4.1.3 Antenna Gain
Antenna gain is a measure of how strongly an antenna radiates in its direction of
maximum radiation intensity compared to how strong the radiation would be if the
same power were applied to an antenna that radiated all of its power equally in
all directions. Using the antenna pattern, the gain is the distance to the furthest
point on the pattern from the origin. For an omnidirectional pattern, the gain is 1,
or equivalently 0 dB. The higher the antenna gain, the narrower the beamwidth,
and vice versa.