Cisco GS7000 Installation And Operation Manual page 47

RF Amplifier Module
Reverse Band Amplification Path Description
The RF amplifier module provides all reverse signal amplification outside the optical
transmitter modules in the 1.2 GHz GS7000 Node. It contains four independent
reverse paths comprised of an AC bypass circuit, a bi-directional 20 dB down reverse
test point, a diplex filter, an input pad, a low pass filter, a 6 dB switched attenuator, a
16 dB gain block, a second low pass filter, an RF on/off switch, a frequency response
trim circuit, and a reverse configuration module. The 6 dB switched attenuator and
RF on/off switch circuits allow each reverse path to have 6 dB (wink) and on/off
capabilities. These circuits are controllable from the headend via the status monitor
or locally via the local control module and a hand held controller. A serial
communication link is provided between status monitor or local control module and
the reverse band launch amplifier. Circuitry on the amplifier converts the serial
communications to parallel control signals and routes them as needed.
The RF amplifier module also provides the routing for the auxiliary ports, 5 to 210
MHz reverse band local injection signals. Each of the two auxiliary port reverse band
local injection paths is comprised of an AC bypass circuit, a bi-directional 20 dB
down reverse test point, an input pad, and a reverse auxiliary
jumper/amplifier/termination module. Signals from port 3 or port 6 of the nodes
auxiliary path are directed by the reverse auxiliary/jumper/amplifier/termination
module to the reverse configuration module.
Reverse Configuration Module
The reverse configuration module determines the reverse path topology in the RF
amplifier module and 1.2 GHz GS7000 Node. The input signals from four
independent amplifier module output ports and possibly the auxiliary reverse
injection amplifier module port enter the reverse configuration module where they
are combined and/or directed to one to four optical transmitters. Reverse path
segmentation and or redundancy as well the ability to locally inject signals into the
reverse path of the amplifier is set by plugging the appropriate reverse configuration
module into the RF amplifier module. The reverse configuration module is a plug-in,
field accessible module. See Reverse Configuration Module (on page 34) for more
information.
Reverse Auxiliary Jumper/Combiner/Amplifier/Termination Module
The reverse auxiliary jumper/combiner/amplifier/termination module determines
how reverse band signals, locally injected into the RF amplifier modules auxiliary
ports, are routed within the amplifier module. The reverse auxiliary jumper module
directs signals for one of the RF amplifiers auxiliary ports to the reverse
configuration module.
The reverse auxiliary amplifier module amplifies signals for one or both of the RF
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