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Dimetra EBTS RF Distribution » History » Version 5

laforge, 02/19/2016 10:52 PM
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{{>toc}}
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h1. RF Distribution System (CFX4041A)
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This is a sophisticated combiner for the high-power output signals of the PA of up to 4 Base Radios.
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In order to ensure optimal impedance matching, the combiner is mechanically tuned by electrical motors
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which are controlled by some control logic.
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The combiner inside the system has the following connections (external connections in *bold*):
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* *4 high-power radio input ports* (N socket on the front, one close to each motor)
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** this is where the RF signal emitted by the PA of the BR enters
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* 4 RF taps, one for each of the high-power radio inputs
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** they are connected to the controller unit attached to the inside of the front lid
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* 1 high-power radio output port (N socket)
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** this output is connected to a power meter inside the same cabinet
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* 4 stepper motor electrical connections
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** connected to the controller unit attached to the inside of the front lid
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* RS-232 serial line for control+monitoring
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** this is a DB-9 port of the controller unit attached to the inside of the front lid
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** interconnected to one of the Base Radios (typically BR1) inside the rack
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The flow of the signals is as follows:
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* RF from the PA enters at the four combiner inputs
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* combined RF output leaves through central output of the combiner, from where
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* it is routed to the FR power meter
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* whose output socket is routed to the transmit antenna (or a duplexer in case of a shared Rx/Tx antenna)
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<pre>
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<code class="graphviz">
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digraph G {
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  graph [ rankdir = LR  ];
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  //{ rank=same; combiner; controller; };
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  br1_pa_out -> combiner
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  br2_pa_out -> combiner
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  br3_pa_out -> combiner
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  br4_pa_out -> combiner
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  combiner -> power_meter
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  power_meter -> tx_antenna
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  combiner -> controller [ dir=both color=red ]
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  power_meter -> controller [ color=red ]
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  power_meter [ shape=box ];
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  combiner [ shape=box ];
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  controller [ shape=box ];
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}
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</code></pre>
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h2. Images ==
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 View into RF Distribution System after front lid is removed ===
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[[Image(tetra_rf_distribution_open.jpg, 75%)]]
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h3. Forward and reverse measurement inputs into controller
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[[Image(tetra_rf_distribution_controller_in.jpg, 75%)]]
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