User's Manual

INTRODUCTION
Confidential, Proprietary Information
Title: PolBEAMER PCS (3.2) Array System-
Assembly and Operation Manual
Doc. No.:
913000801
Rev.: 01
Page: 16 of 91
1.3.3. RF Path Description
1.3.3.1. Tx/Rx Active Bias-T Block Diagram
The Active Bias-T contents a boost amplifier and a digital controlled attenuator in order to
adjust the gain and enable a convenient interface to the BTS. The gain of the ABT
assemblies is Temperature Compensated. Block diagrams for this ABT are shown the
following figure.
REGULATION
+PROTECT
P
A
LN
A
GAIN CONTROL
DUPLEXER
P
A
CURRENT
INDICATOR
GAIN CONTROL
5
DC Supply
RF + DC
+8V
to Rx
From BTS
Tx Output
To BEAMER
Array
Tx Active Bias-T Block
Rx Active Bias-T Block
P.
A
GAIN CONTROL
From
BEAMER
Array
RF + M&C
DUPLEXER
+8V
from Tx
Rx Amp
Current
Indicator
GAIN
CONTROL
5
M&C Port
REGULATION
+PROTECT
To BTS
Rx Input
Figure 5: Active Bias-T block diagrams
1.3.4. Bias-T Types
The ICU is equipped with Rx ABTs and Tx ABTs. The Rx ABT can be one of several types,
which differ in the available gain from –4 db to +28db