Dimetra EBTS RF Distribution » History » Version 5
laforge, 02/19/2016 10:52 PM
add pics
1 | 5 | laforge | {{>toc}} |
---|---|---|---|
2 | 1 | laforge | |
3 | 5 | laforge | h1. RF Distribution System (CFX4041A) |
4 | |||
5 | |||
6 | 1 | laforge | This is a sophisticated combiner for the high-power output signals of the PA of up to 4 Base Radios. |
7 | |||
8 | In order to ensure optimal impedance matching, the combiner is mechanically tuned by electrical motors |
||
9 | which are controlled by some control logic. |
||
10 | |||
11 | 5 | laforge | The combiner inside the system has the following connections (external connections in *bold*): |
12 | * *4 high-power radio input ports* (N socket on the front, one close to each motor) |
||
13 | ** this is where the RF signal emitted by the PA of the BR enters |
||
14 | * 4 RF taps, one for each of the high-power radio inputs |
||
15 | ** they are connected to the controller unit attached to the inside of the front lid |
||
16 | * 1 high-power radio output port (N socket) |
||
17 | ** this output is connected to a power meter inside the same cabinet |
||
18 | * 4 stepper motor electrical connections |
||
19 | ** connected to the controller unit attached to the inside of the front lid |
||
20 | * RS-232 serial line for control+monitoring |
||
21 | ** this is a DB-9 port of the controller unit attached to the inside of the front lid |
||
22 | ** interconnected to one of the Base Radios (typically BR1) inside the rack |
||
23 | 1 | laforge | |
24 | The flow of the signals is as follows: |
||
25 | 5 | laforge | * RF from the PA enters at the four combiner inputs |
26 | * combined RF output leaves through central output of the combiner, from where |
||
27 | * it is routed to the FR power meter |
||
28 | * whose output socket is routed to the transmit antenna (or a duplexer in case of a shared Rx/Tx antenna) |
||
29 | 1 | laforge | |
30 | 5 | laforge | <pre> |
31 | <code class="graphviz"> |
||
32 | 1 | laforge | digraph G { |
33 | graph [ rankdir = LR ]; |
||
34 | |||
35 | //{ rank=same; combiner; controller; }; |
||
36 | |||
37 | br1_pa_out -> combiner |
||
38 | br2_pa_out -> combiner |
||
39 | br3_pa_out -> combiner |
||
40 | br4_pa_out -> combiner |
||
41 | |||
42 | combiner -> power_meter |
||
43 | power_meter -> tx_antenna |
||
44 | |||
45 | combiner -> controller [ dir=both color=red ] |
||
46 | power_meter -> controller [ color=red ] |
||
47 | |||
48 | power_meter [ shape=box ]; |
||
49 | combiner [ shape=box ]; |
||
50 | controller [ shape=box ]; |
||
51 | } |
||
52 | 5 | laforge | </code></pre> |
53 | 1 | laforge | |
54 | 5 | laforge | |
55 | h2. Images == |
||
56 | View into RF Distribution System after front lid is removed === |
||
57 | 3 | laforge | [[Image(tetra_rf_distribution_open.jpg, 75%)]] |
58 | 4 | laforge | |
59 | 5 | laforge | |
60 | h3. Forward and reverse measurement inputs into controller |
||
61 | |||
62 | 1 | laforge | [[Image(tetra_rf_distribution_controller_in.jpg, 75%)]] |