User's Manual Part 1

Table Of Contents
3EM21522AAAA Functiona
l
Description
Issue 1, March 2008 DTR-0200-SA-SIRIUS
2-17
2.4
HIGH POWER AMPLIFIER (HPA)
See
Figure 2 - 10
and
Figure 2 - 11
for the HPA sub-assembly front and rear panels and
the HPA functional block diagram.
The HPA amplifies the S-Band terrestrial signal to an output level of 200 watts
(after the output filter).
The HPA is a solid-state device operating in Class A/B linear
mode over a frequency range of 2305 MHz to 2360 MHz and is fully protected against
input overdrive, temperature, and output load VSWR conditions. The protection cir-
cuitry is self-correcting and allows restoration of the HPA to normal operation upon
removal of the fault.
The HPA is a separate sub-assembly Least Replaceable Unit (LRU) installed on slid-
ing rails in the repeater enclosure. It contains an integrated AC/DC power supply, a
pre--driver
, a driver, a 5-way splitter, five individual power amplifier modules, a 5-
way combiner, and an HPA controller.
Figure 2 - 10 HPA Panels