User Manual

Axell Wireless Limited
Technical Literature
L.A. M.T.A. Remote Sites
Document Number 80-301401HBKM Issue No. 1 Date 13/06/2008 Page 119 of 148
4.11. UHF Midband Amplifier Shelf 80-301410
UHF Midband Amplifier Shelf 80-301410 provides the amplification stages for the UHF Midband
paths, The unit is housed in a 4U, 19” rack mount shelf which is mounted in Rack 1
The Downlink UHF Midband signal is received at the port labelled “UHF DOWNLINK I/P” (Annotated
A in section 4.11.4.2.). The signal passes through a switched attenuator providing 0 to 30 dB of RF
signal attenuation and then into the amplification stage. The Downlink UHF Midband amplification
stage is provided by two amplifier modules, the first is a 15dB gain Low Power Amplifier and the
second is a 20W, 23dB gain power amplifier. Both amplification stages are straddled by an Automatic
Gain Control assembly providing limiting to the output signals in the case of high input signals.
The input to the AGC detector is provided by the output of a 30dB tap. After leaving the
Amplification/AGC stage the Downlink UHF Midband signal exits the Shelf via the port labelled “UHF
DOWNLINK O/P” (B in section 4.11.4.2.).
The Uplink UHF Midband signal is received at the port labelled “UHF UPLINK I/P” (Annotated C in
section 4.11.4.2.). The signal passes into a Low Noise Amplifier providing 15dB of gain and then into
a switched attenuator providing 0 to 30 dB of RF signal attenuation. After the attenuator the Uplink
UHF Midband signal passes into a second stage of amplification provided by a 5W, 30dB gain Power
Amplifier, this amplification stage is straddled by an Automatic Gain Control assembly providing
limiting to the output signals in the case of high input signals.
The Uplink UHF Midband signal exits the Shelf via the port labelled “UHF UPLINK O/P” (D in section
4.11.4.2.).
UHF Midband Amplifier Shelf 80-301410 is provided with a 24V DC input to power the amplifier
modules within and those amplifier modules are configured to provide alarm status reports.