User's Manual

Page 12 of 21
IDEN Digital Repeater Installation
Manual
9
REPEATER (BDA) OPERATION
The RF connection is made via two type “N” female connectors. The RF connector labeled
“Base” must be connected to the antenna pointing to the base station; usually a rooftop antenna.
The RF connection labeled “Mobile” must be connected to the antenna pointing into the area to
be covered by the Repeater such as inside a building or outdoor shaded area.
The repeater operates from 110V/220 VAC @ 2A.
9.1 AGC (ALC) FUNCTION
The repeater has AGC (Automatic Gain or Level Control) function on both paths that serve to
prevent the saturation of the power amplifier. The amplifier has a directional coupler and a
detector at the output of the high power amplifier to monitor the output power. When a high
signal is received the automatic level control detects the amplitude and sends a feedback signal to
a voltage variable attenuator that attenuates the signal level so that the output power of the
amplifier does not exceed the preset limit. This level control ensures the power amplifier
operation in the linear region only.
9.2 RF GAIN SETTING
For proper operation of the Repeater, the isolation between the base station antenna and the
mobile antenna should exceed the Repeater gain by at least 10 dB. If the Repeater gain is higher
than the isolation between the antennas, oscillation will build up and will saturate the amplifier.
The step attenuator on the low noise amplifier can reduce the Repeater gain. The repeater gain
can be reduced by 31 dB in 1 dB steps.