User's Manual

68P80801H45-1 1/20/2002 9
EBTS System Manual - Vol 2 Power Amplifier (PA)
PA Theory of Operation
Interconnect Board
(70W-800 MHz, 40W-800
MHz, 800 QUAD, and 900
MHz QUAD
• Provides RF interconnection from the LDM to the RF Splitter board
• Provides DC supply filtering
RF Splitter/DC board • Interfaces with the DC/Metering Board to route DC power to the
LFMs
• Interfaces with the DC/Metering Board to route PA Bias Enable to
the six Linear Final Modules (900 MHz Quad)
• Contains splitter circuits that split the RF output signal of the LDM
to the three Linear Final Modules (40W- 800 MHz)
• Contains splitter circuits that split the RF output signal of the LDM
to the six Linear Final Modules (70W- 800 MHz, 800 MHz QUAD
and 900 MHz QUAD)
• Contains a Quadrature splitter circuit to split the RF output signal of
the LDM to the two Linear Final Modules (900 MHz and 1500 MHz)
Linear Final Module
(LFM)
• Each module contains two Class AB amplifiers in parallel. Each
module amplifies one of three RF signals (~ 84 W average power)
from the LDM (via the Splitter/DC board). Three LFMs provide a
sum RF output of approximately 48 W average power, before losses.
(40W, 800MHz)
• Each module contains two Class AB amplifiers in parallel. Each
module amplifies one of six RF signals (~ 8 W average power) from
the LDM (via the Splitter/DC board). Six LFMs provide a sum RF
output of approximately 97 W average power, before losses. (70W,
800MHz)
• Each module contains two Class AB amplifiers in parallel. Each
module amplifies one of six RF signals (~6W average power) from
the LDM (via the splitter/DC Board). Six LFMs provide a sum RF
output of approximately 73W average power , before losses. (800
MHZ QUAD* and 900 MHz QUAD*)
• Each module contains two Class push-pull AB amplifiers in parallel.
Each module amplifies one of two RF signals (~ 17 W average
power) from the LDM (via the Splitter/DC board). Two LFMs
provide a sum RF output of approximately 75 W average power,
before losses. (900MHz)
• Each module contains two push-pull Class AB amplifiers in parallel.
Each module amplifies one of two RF signals (~ 16 W average
power) from the LDM (via the Splitter/DC board). Two LFMs
provide a sum RF output of approximately 56W average power,
before losses. (1500MHz)
RF Interconnect Board
(40W- 800 MHz PA only)
• Contains three transmission lines that interconnect the LFMs to the
RF Combiner/Peripheral Module
Combiner Board
(70W-800 MHz PA, 800
MHz QUAD, 900 MHz
QUAD)
• Contains three separate Quadrature combiner circuits that
respectively combine the six RF outputs from the LFMs into three
signals. These three signals, in turn, are applied to the RF Combiner/
Peripheral Module.
Table 2
Power Amplifier Circuitry (Continued)
Circuit Description