User Manual

BDA OVERVIEW:
The BDA assembly extends the coverage area of radio communications in
buildings and RF shielded environments.
The unit features low noise figure and wide dynamic range. It is based on a
duplexed path configuration with sharp out of band attenuation allowing improved
isolation between the receiving and transmitting paths.
BDA CIRCUIT DESCRIPTION
:
Refer to figure 1 for the following discussion.
The BDA Downlink path receives RF signals from the base station and amplifies
and transmits them to the subscriber. The BDA Uplink path receives RF signals
from the subscriber and amplifies and transmits them to the base station. The
Uplink and Downlink occupy two distinct frequency bands. For example, the
CELL B frequency bands are as follows: 835-849 MHz for the Uplink and 880-
894 MHz for the Downlink. Two diplexers isolate the paths and route each signal
to the proper amplifying channel.
A selectable Automatic Level Control (ALC) allows for output power limiting. A
variable step attenuator gives 0 – 30 dB of attenuation in 2 dB steps. The use of
these controls is covered in the “OPERATION” section, later in this document.
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