Harris Atlas DVL400, Техническое руководство

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4-18 888-2473-001 2/25/03
WARNING: Disconnect primary power prior to servicing.
Section 4 Theory of Operation ATLAS Series™
The PA Module is made up of the following components:
a. Phase and Gain Board
b. Predriver pallet (actually 1/2 of an amplifier pallet)
c.
Two driver pallets
d.
Two 4-way RF splitters
e.
Eight (8) Power Amplifier pallets
f.
Eight (8) way pallet combiner (not to be confused with the 8-way Module
combiner)
g. Directional Coupler for Forward and Reflected power metering and protec-
tion
h. Liquid cooled heatsink or cold-plate
i. PA Module Control Board (this includes a micro module)
j.
DC Distribution board (+32V switch) with pallet current and voltage sensing.
4.4.4.1 Phase and Gain Board
The RF enters the module and is routed directly to the Phase and Gain Board. This
board provides several functions which are key to operation of the module:
a. It acts as a gain block to increase the RF input to a level that is sufficient to
drive the predriver pallet.
b.
It has an RF input switch which is used to mute and un-mute the RF through
the module.
c. Input power sampling for metering and Input over-drive detection.
d. Receives I and Q vector control signals from the Module Controller Board
which are used for module insertion phase and gain. This allows all of the
modules to be adjusted for best phase and gain by the Main Controller in
order to reduce the reject power in the module combiner and optimise PA
efficiency. For 2 cabinet systems, all modules in a cabinet can be adjusted at
the same time to permit cabinet phase and gain adjustment to minimise the
cabinet combiner reject power. All phase and gain adjustments are done from
the GUI.
e.
Automatic Level Control or ALC to keep the power output of the module
constant.
The RF output from the Phase and gain board connects to the Predriver pallet