The SwissCube telecommunication system includes two data transmission types. A beacon signal (20.8 dBm or 120mW, 10 bits/sec in Morse code at 437 MHz) is constantly operational and is switched off by a command from the ground to be replaced by the main RF data transmission. This main data stream sends the scientific and engineering telemetry at 1200 bits/sec at an output power of 30 dBm (1W) and is FSK modulated at a frequency of 437 MHz. The uplink signal uses the 145 MHz carrier frequency and is AFSK modulated.

Since in the stowed configuration, SwissCube shall not exceed 10cm on a side, and since two antennas are used to communicate with the ground stations, an antenna deployment system is used. The VHF antenna is 610 mm long when the antenna is in straight ideal position. The UHF antenna of 176 mm when the antenna is in straight ideal position.

A critical requirement for the deployment system is high reliability. This has to be achieved with several other constraints like mass, volume and power consumption. The mass for the antenna system is 25g. The volume used in the interior of the satellite has to be kept as small as possible and it shall not protrude out of the face of the cube more than 6.5mm. In addition to that, the system has to fulfill all the compatibility criteria for space applications.


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