User Manual

Table Of Contents
Preparation | 19
3. Preparation
Path planning
Proper path planning is essential. When considering the components of your radio system, think
about:
antenna selection and siting
coaxial cable selection
link budget
You can also use Surveyor to help you with path feasibility planning.
Surveyor is a path propagation calculator developed by 4RF to assist path planners quickly and
efficiently verify the viability of point-to-point transmission links deploying the Aprisa™ microwave radio
systems.
The software program calculates the anticipated link performance for the transmission system
elements you have selected. However, it is not a substitute for in-depth path planning.
You will find Surveyor a valuable addition to your planning toolbox.
A copy of Surveyor is provided on the Aprisa CD supplied with this manual. You can download
updates from
www.4rf.com.
Antenna selection and siting
Selecting and siting antennas are important considerations in your system design.
There are three main types of directional antenna that are commonly used with the radios parabolic
grid, Yagi and corner reflector antennas.
The antenna that should be used for a particular situation is determined primarily by the frequency of
operation and the gain required to establish a reliable link.
Parabolic grid antennas
Factor Explanation
Frequency Often used in 1350-2700 MHz bands
Gain Varies with size (17 dBi to 30 dBi
typical)
Wind loading Can be significant
Tower aperture required Can be significant
Size Range from 0.6 m to 3 m diameter
Front to back ratio Good
Cost High