(4) If a single carrier is to be transmitted, the
(defined as the portion of the terminal from IF input to the
output of the on-line upconverter drives the on-line power
SHF output of the power amplifier) consists of a
amplifier. The power amplifier is a five cavity Klystron
redundant configuration of amplifier/mixer, power
amplifier tunable over the 500 MHz transmit band with
amplifier and high voltage power supply configured as
five calibrated tuning adjustments accessible through a
on-line and off-line units. The selection of on-line units
small door in the front panel. The output of the power
is performed by manual patching between appropriate
amplifier goes to the antenna " through a manual
connectors on the transmit patch panel and the inputs
waveguide switch which is used to select the on-line and
and outputs of every unit shown in the block diagram of
off-line unit. Power from the offline unit is routed to a
(5) If multiple carriers are to be transmitted,
the 70 MHz input to the on-line upconverter is translated
the output of each on-line upconverter is routed to the
to 700 MHz. After amplification and filtering, the 700
online amplifier/mixer unit. This unit is used to set the
MHz is translated to the transmit output frequency of 7.9
relative power levels of the carriers and reamplify the
to 8.399999 GHz.
combined signal to drive the on-line power amplifier.
(3) The output of the upconverter is filtered
(6) The off-line power amplifier is terminated
and amplified by a solid state intermediate power
in a dummy load allowing the unit to be turned on and
amplifier to a level suitable for driving either the
monitored. Each power amplifier has a high efficiency
amplifier/mixer or the power amplifier. The upconverter
switching converter, high voltage power supply and
drawers contains an upconverter, frequency synthesizer,
complete monitoring capability. The output of the online
intermediate power amplifier and power supply.
power amplifier is then routed to the transmit port of the
antenna for transmission to the satellite.
b. Receive Section. Figure 1-4 shows a functional
block diagram of the receive section of the terminal.