MT-MR PLATINUM. POINT TO POINT AURAL RADIO RELAY SYSTEM
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MT-MR PLATINUM
POINT TO POINT AURAL RADIO RELAY SYSTEM
chapter I
PREVIOUS PATH CALCULATIONS.
1.1.- Introduction
As a preliminary knowledge, it's necessary to calculate what is the type of link we need to buy in order to solve our
particular case, or if we have a certain set of equipments and antennas previously adquired, what are the
capabilities of that system to cover the planned distance with the minimum required signal strength in order to assure a
long-term, noise-free transmission of video and /or audio information through this way. Prior to install a certain
system, Engineers have to perform some preliminary calculations to guarantee that these results will be reached.
Main factors determining the reliability of a certain Microwave analogic link are the following, particularly in the
bands starting from 1 GHz and ending in 12 GHz :
1.1.1.- Free Space Attenuation of propagated RF signal.
1.1.2.- Presence of obstructions in the propagation path.
1.1.3.- Possible Reflection Points of propagated signal.
1.1.4.- Transmission lines and antennas used in the system.
1.1.5.- Any other RF elements and components installed through the transmission path, such as filters,
circulators, diplexers, etc. attenuating in a higher or lower degree the propagated signal strength.
1.1.6.- Transmitter power output and receiver sensitivity & noise figure.
1.1.7.- Propagation path free space clearance at radio waves frequency.
Through this Introductory Study, we should briefly talk about these factors determining the behavior of any Analogic
Radio Relay Link:.
1.2.- Free Space Attenuation.
Atmospheric or Free Space Attenuation within the direct path between Transmitter and Receiver sites, is a function
of the system transmission frequency and the distance between both sites. This expression is affected by a
coefficient depending on the Earth's region where the link will be installed, and is determined by estatistical
calculations in an empirical form :
