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In the transmit direction, the antenna converts the RF signals transmitted from the ODU
into the directional electromagnetic waves and then radiates the electromagnetic waves in
the air.
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In the receive direction, the antenna receives and assembles the electromagnetic waves
from the air, converts the electromagnetic waves into the RF signals, and then transmits
the RF signals to the ODU.
4.3 Working Principle
An antenna comprises the reflector, feed boom, radome, shield, and mounting brackets.
shows the structure of the antenna.
NOTE
This topic considers the single-polarized antenna as an example to describe the working principle of
antennas. The dual-polarized antenna has two feed boom interfaces and thus can transmit the
electromagnetic waves in the vertical and horizontal polarization directions at the same time. The working
principles of each component of the dual-polarized antenna are similar to the working principles of each
component of the single-polarized antenna.
Figure 4-4
Structure of the antenna
5
1
2
3
4
1. Feed boom
2. Reflector
3. Shield
4. Radome
5. Mounting brackets
The functions of each component of the antenna are described as follows:
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Feed boom
The input port of the feed boom accesses the RF signals transmitted from the ODU. The
accessed RF signals are transmitted through the waveguide to the output port of the feed
boom, which is located at the focal spot of the reflector. The output port of the feed boom
is equivalent to a preliminary horn antenna and radiates electromagnetic waves towards the
antenna reflector.
You can change the polarization direction of the antenna by rotating the feed boom. The
polarization direction of the antenna is the polarization of the electromagnetic waves
4 Antenna
OptiX RTN 600 ODU
Hardware Description
4-4
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
Issue 06 (2010-05-30)