Satellite communication has extensive applications in modern society. It uses satellites as a medium to achieve global signal transmission. In this process, the choice of antenna plays a crucial role in the quality of signal transmission. In recent years, in the field of satellite communication antennas, phased array antennas have gradually replaced traditional parabolic antennas due to their efficient performance, especially in highly mobile and space-constrained scenarios. This article will delve into the working principles, advantages, and applications of phased array antennas in satellite communication.
Phased array antennas have significant differences from traditional parabolic antennas. Traditional parabolic antennas rely on mechanical rotation to align with satellite signals, while phased array antennas achieve this function through electronic scanning technology. Phased array antennas in satellite communication can accurately control the direction of the beam by adjusting the phase shifters, thereby capturing satellite signals.
Once the incident angle of the satellite signal is determined, the phase shifters can adjust the phase to produce the maximum signal gain in the current angle direction. Unlike parabolic antennas, phased array antennas do not rely on mechanical transmission devices, resulting in a faster response to satellite signals. This is particularly advantageous in high-speed moving scenarios, such as on aircraft and ships, where the use of phased array antennas in satellite communication can significantly improve signal tracking and reception efficiency.
Phased array antennas' working mechanism also makes them highly adaptable to changes in platform posture. When the orientation of the carrier changes, the incident angle of the satellite signal might also change. The system can quickly calculate the new incident angle and adjust the phased array antenna beam to remain aligned with the satellite. This feature makes phased array antennas irreplaceable in low-orbit satellite communication systems, such as the ground receiving antennas in the Starlink system that use phased array technology.
Phased array antennas' greatest advantage lies in their low profile and fast response speed, making them especially suitable for space-constrained installations such as airborne and shipborne scenarios. Traditional parabolic antennas require large mechanical structures to make adjustments, while phased array antennas use electronic scanning technology, eliminating the need for mechanical rotation and greatly reducing the volume and weight of the equipment. This lightweight design allows satellite communication antennas to be more flexible in various complex environments, and particularly in applications requiring rapid antenna angle adjustments, phased array antennas can almost complete the beam adjustment within milliseconds.
Compared to mechanical structures, phased array antennas also have an advantage in tracking low-orbit satellites. Low-orbit satellites move quickly, and traditional parabolic antennas need to constantly adjust their angles to maintain the connection with the satellite, increasing system complexity and potentially causing signal delays and interruptions. Phased array antennas' electronic scanning technology can quickly adjust the beam direction, ensuring the stability and reliability of satellite communication.
Additionally, phased array antennas have a unique advantage in low elevation angles by design. When the angle between the satellite signal and the normal of the antenna is relatively small, the antenna can still maintain a high gain. Even when the satellite is not directly overhead, phased array antennas can adjust the beam direction by calculating the incident angle, ensuring a smooth communication link. Compared to traditional parabolic antennas, satellite communication antennas using phased array designs can better handle satellite signal incidents from different angles, improving communication stability and quality.
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