The Research on Spacecraft TT&CUnwanted Emission Suppression

The frequency requirements of the spacecraft TT & C (Tracking, Telemetry & Command) are growing rapidly. The frequency utilization is faced with the situation of large numbers of wireless devices on the satellites and launch vehicle, the wide occupied band, narrow frequency band interval. The frequency bands allocated to the space operation service are becoming more congested. For using frequency more efficiently, satisfying the electromagnetic compatibility (EMC) among the satellite, the launch vehicle and the earth stations, the unwanted emission suppression applying to the different modulation and data rates is presented. The new unwanted emission masks take into account the modulation, data rate, the actual filtering capabilities of the system and will decrease the required guard bandwidth to the adjacent band users.