Motorola DIMETRA MTS 2, Installation, Configuration And Basic Service Manual

Page: 239 / 517

Chapter
7
Radio Frequency Distribution System
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This chapter contains the following topics:
•
"RFDS Theory of Operation"
•
"MTS 2 RFDS"
•
"MTS 4 RFDS"
•
"Expansion Cabinet RFDS"
The Radio Frequency Distribution System (RFDS) distributes and manages the communications
network frequencies and mitigates interference between multiple radios, allowing them to
operate simultaneously. This results in improved radio reception performance across the
frequency ranges where multiple transmitters are broadcasting.
RFDS Theory of Operation
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The RFDS module is made up of the following subcomponents:
•
Preselector (MTS 2 and MTS 4)
•
Duplexer (MTS 2 and MTS 4)
•
Cavity Combiners (MTS 4 and Expansion Cabinet)
•
Hybrid Combiner (MTS 2, MTS 4 uses either HC or CC)
•
Post Filter (MTS 4 only)
•
RX Splitter (Expansion Cabinet only)
The RFDS module supports the combining and
fi
ltering of multiple Base Radio transmitters to one or more
antenna outputs. The RFDS module supports up to triple receive diversity. Signals are
fi
ltered by either the
Duplexer or the Preselector, then ampli
fi
ed and distributed by the integrated Receiver Multicoupler (RMC). In
con
fi
gurations with an Expansion Cabinet, the RX-splitter is used to distribute the received signal.
The RFDS also conditions the transmit and receive signal using
fi
lters. After combining the Base Radio
transmitters in the Hybrid Combiner (or in the Cavity Combiner in the case of the MTS 4), the transmit signals
are
fi
ltered in the transmit path of the Duplexer, which supplies the antenna connector on the cabinet.
6802800U74-N September 2009
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