What are the Classifications of Satellite Ground Terminal?

The Composition of Satellite Ground Terminal

There are various ground terminals used in various satellite communication systems, and a typical duplex ground terminal equipment should include a channel terminal subsystem, high-power transmission subsystem, high-sensitivity receiving subsystem, antenna feed subsystem, servo tracking subsystem, power supply subsystem, and monitoring subsystem.

Channel terminal subsystem: the function of the transmitting equipment in the channel terminal subsystem is to deal with the baseband signal and modulate the intermediate frequency (such as 70MHz); The function of receiving equipment is opposite to the above process. Channel terminal equipment can be divided into analog channel terminal equipment and digital channel terminal equipment according to different signal processing; According to the communication service, it can be divided into TV, telephone, data, and other channel terminal equipment.

Transmission subsystem: in the standard ground terminal, it is necessary to transmit hundreds or even tens of thousands of watts of high-power microwave signals to the satellite. In order to realize multiple access communication, several carriers are often transmitted to other ground stations at the same time. Therefore, the ground station shall be able to work under the conditions of high voltage, high power, broadband, and multi-carrier. The system includes an up converter, automatic power controller, transmit wave synthesizer, exciter, and high power amplifier.

The Classifications of Satellite Ground Terminal

The basic function of the satellite ground terminal is to transmit signals to the satellite and receive the signals transmitted by other ground terminals via the satellite. Depending on the nature and use of the satellite communication system, there may be different forms of ground terminals. For example, it is classified according to whether the station site is fixed or not, the size and purpose of the g/t value, antenna aperture, and the characteristics of the transmission signal.

1. classification according to station site characteristics: it can be divided into a fixed station, a mobile station (such as a shipborne station, airborne station, vehicle-mounted station, etc.), and a removable station (the station that can dismantle the transfer site in a short time). Fixed stations can be divided into large-scale standard stations and small-scale non-standard stations. The former is mostly used for international communication and communication between domestic big cities, while the latter is mostly used for domestic medium and small cities or military communication; Mobile ground station, especially vehicle-mounted station, is widely used in military communication because of their flexibility.

2. classification by g/t value: the ground station performance index g/t value is an important technical performance index reflecting the ground station receiving system. Where G is the gain of the receiving antenna and t is the equivalent noise temperature representing the noise performance of the receiving system. The larger the g/t value, the better the performance of the ground station receiving system.

3. classification by purpose: it can be divided into civil, military, broadcasting, navigation, experiment, and other ground stations.

4. classified by antenna aperture: it can be divided into 1m stations, 5m station, 10m station, 30m station, etc.