Title :
Evolution of Space TWT Requirements and Specifications for Modern Communication Satellites
Author :
Aloisio, Marinella ; Casini, Enrico ; Ginesi, Alberto ; Waller, Pierre
Author_Institution :
RF Payload Syst. Div., Eur. Space Agency
Abstract :
Complex, non-constant envelope, high order digital modulation schemes used in modern communication satellites bring new requirements for the linearity and power efficiency of the traveling-wave tubes (TWT). As a result, a reassessment of the typical TWT specifications is in order. A digital system-level figure-of-merit, the total degradation (TD), is proposed. It accounts for the characteristics of any coded digital system and the performance of the overall communication link, including co-channel and adjacent channel interference. This figure-of-merit allows re-optimizing the operating point of currently used TWTs, comparing the end-to-end performance of different tubes and revising the standard TWT linearity-versus-efficiency requirements
Keywords :
adjacent channel interference; satellite communication; travelling wave tubes; TWT specifications; adjacent channel interference; cochannel interference; coded digital system; communication satellites; digital modulation schemes; space travelling wave tubes; total degradation; Artificial satellites; Degradation; Digital modulation; Digital systems; Digital video broadcasting; Interchannel interference; Linearity; Modulation coding; Radio frequency; Satellite broadcasting; Communication satellites; Total Degradation (TD); Traveling-wave Tube (TWT); efficiency; high order digital modulation schemes; linearity; optimization;
Conference_Titel :
Vacuum Electronics Conference, 2006 held Jointly with 2006 IEEE International Vacuum Electron Sources., IEEE International
Conference_Location :
Monterey, CA
Print_ISBN :
1-4244-0108-9
DOI :
10.1109/IVELEC.2006.1666183
