Specifications

Operations Manual, Redundant System Controllers 209351 REV B 49
4.3 Operation of 1:1 Fixed Phase Combined System with FPRC-1100
The 1:1 Fixed Phase Combined Redundant System is a popular system architecture
that enables two Solid State Power Amplifiers to operate as a normal 1:1 redundant
system or a phase combined system. The basic system topology is very similar to a
1:1 redundant system and is shown in Figure 4-9. An additional switch is included
which allows either amplifier to be individually routed to the antenna or connect both
amplifiers to a waveguide combiner. The combined system output power is then routed
to the antenna. The operation is very similar to the older generation variable phase
ratio combiner (VPRC) techniques.
System designers find that the 1:1 Fixed Phase Combined Amplifier System topology
is a cost effective solution to realizing higher power amplifier systems. For slightly more
investment over a traditional 1:1 redundant system, the operator can have the capabil-
ity of doubling the individual amplifier output power when conditions may require addi-
tional power. This is helpful when either atmospheric conditions require more power or
if additional satellite traffic requires higher power capacity.
The FPRC-1100 controller is specifically designed to handle such an amplifier system.
It not only handles all of the traditional fault monitoring and switching duties but also
provides an overall system monitor and control facility. The FPRC-1100 can adjust the
system gain over a 20 dB range without the need to adjust each of the amplifiers
individually. It also provides a convenient display of the overall system output power.
Individual amplifier monitor and control can all be achieved through the FPRC-1100
either locally via the front panel or by remote serial communication.
RF Output
Amp 1
Amp 2
RF Input
Figure 4-9: Block Diagram, 1:1 Fixed Phase Combined System