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3.2 Antenna Operation principle
The C-band or Ku-band 12m Cassegrain antenna can be supplied with two ports (RX/TX) or
four ports (2TX/2RX). The operation principles are described as follows.
Antenna receiving principles
：
the antenna aligns satellite, the satellite signals are transmitted
via main reflector and subreflector to the feed, then output from the corresponding port of
feed and finally sent to the tracking receiver after LNA amplification.
Antenna transmitting principles: the transmitting signals are sent from HPA to the feed via
waveguide and radiated by the feed, then reflected to the free space via main reflector and
subreflector of antenna and propagated to satellite.
The antenna can simultaneously transmit and receive electromagnetic wave signals. The
step tracking mode (optional) is used to make the antenna be able to align the satellite.
4 Maintenance
As outdoor equipment, the antenna is exposed to natural environment such as wind, rain and
sun. The life of the equipment is greatly affected by correct operation and maintenance.
High-quality maintenance in time is very important to guarantee the service life of the
equipment.
To ensure the service life of the outdoor equipment, follow the requirements described below
for operation and maintenance.
4.1 Operation and Maintenance of Antenna
a) Pay attention to the local weather forecast. When strong wind higher than 32m/s is
coming, make preparations in advance so as to lock the antenna toward the sky with pin
at any time.
b) Once the subreflector has been installed and adjusted well and put into use, nobody is
allowed to go up onto the subreflector support. If it is necessary to go onto it for
maintenance, it is prohibited to step on the subreflector to prevent the installation
accuracy of the subreflector from being changed.
