User's Manual

BDA1300 Equipment Manual
DCM000000018
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Kaval Telecom Inc. Page 2-4 of 51
2 INTRODUCTION TO BDA’s
Bi-Directional Amplifiers (BDA’s) are radio frequency amplifiers that amplify signals in two
directions. There are two basic BDA Applications; Line Amplifiers and “Off-the-Air”...
2.1 BDA Line Amplifier System Application
In-building RF distribution system usually takes on one of several forms including, but limited to,
radiating cable, distributed tapped radiators, or high power repeater antennas. For in-building RF
distribution system that requires some gain to compensate for the system loss, line amplifier is the best
device for the job. Line Amplifiers provides amplifications of RF signals to recover signal loss
contributed by radiating cable and other system components.
Figure 1-1 shows an example of a subway tunnel RF distribution system using Line Amplifiers. The
system consists of Line Amplifiers strategically inserted between radiating cables. As the RF signal
travelling along the radiating cable, it loses strength because some of its energy is converted into heat.
Line amplifiers recover the RF loss by amplifying the signal to the desired signal strength before
sending it down the next section of radiating cables. Hence, the in-building RF seamless coverage can
be maintained.
2.2 BDA Line Amplifier Diagram