4RF Aprisa XE, Руководство пользователя

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Preparation | 21
Corner reflector antennas
Factor Explanation
Frequency Often used in 330-960 MHz bands
Gain Typically 10 dBd
Wind loading Less than a parabolic grid antenna
Tower aperture required About the same as a parabolic grid
antenna
Size Range from 0.36 m to 0.75 m in length
Front to back ratio High (typically 30 dB)
Beamwidth Broad (up to 60°)
Cost Medium
Antenna siting
When siting antennas, consider the following points:
ƒ A site with a clear line of sight to the remote terminal is needed. Pay particular attention to trees,
buildings, and other obstructions close to the antenna site.
Example of a clear line-of-sight path
ƒ Any large flat areas that reflect RF energy along the link path, for instance, water, could cause
multi-path fading. If the link path crosses a feature that is likely to cause RF reflections, shield the
antenna from the reflected signals by positioning it on the far side of the roof of the equipment
shelter or other structure.
Example of a mid-path reflection path
ƒ The antenna site should be as far as possible from other potential sources of RF interference such
as electrical equipment, power lines and roads.
ƒ
The antenna site should be as close as possible to the equipment shelter.
Note: Wide angle and zoom photographs taken at the proposed antenna location (looking down the
proposed path), can be useful when considering the best mounting positions.