Конструктор спутника "ОрбиКрафт"

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High-frequency transmitter
Virtual consumption - 6100 mA

The radio communication system is one of the key service of on-board systems. However, like many engineering systems it does not have an ideal solution. Designing each device you need to search for a balance between the data transfer rate and the power consumption of the on-board radio equipment as well as between the width of the antenna directional pattern and its efficiency. Each new satellite project requires special approaches to solve the problem of data exchange between the board and the Earth.

The standard solution is to install low-speed communications equipment on the satellite to transmit telemetry via the “board-to-Earth” line and control commands to the satellite via the “Earth-to-board” line. As a rule, in this case the satellite is equipped with either an omnidirectional antenna or a system of spot beam antennas. Such a system allows communication with the spacecraft irrespective of its orientation and rotation speed; it consumes low power but also provides small data transfer speed (about 9600 bps).

Another option is to use a high-frequency high-speed transmitter with a spot beam antenna to transmit payload information to the Earth on the “board-to-Earth” line. The data transfer speeds in this way are tens and hundreds of megabits per second. However, such equipment consumes more power and requires precise orientation of the on-board antenna (and hence of the entire satellite) relative to the Earth in order to get the directivity diagram of the on-board antenna to the ground receiving station.

High-frequency (HF) high-speed transmitter is implemented as a separate module in the construction set including a simple LED that flashes with a specified frequency and a certain sequence. At the moment when the light from this “transmitter” gets on the high-frequency receiver to the Earth, it is considered that the communication channel is opened and it is possible to transmit the data of photos from the satellite to the ground (in reality - via WiFi network).

The high-frequency transmitter is one of the main consumers of electricity on board the satellite. It is highly discouraged to keep it permanently on if there is no special need for it: too much load on the power supply system will lead to a quick accumulator slump and emergency deactivation of the “board”.