Title :
Handling the RF output of high-power TWTAs in spacecraft
Author_Institution :
Comsat Lab., Clarksburg, MD, USA
fDate :
30 Sep-3 Oct 1990
Abstract :
The radiated power demands of Ku-band communications satellites are currently being met by a generation of high-efficiency helix traveling wave tubes (TWTs) capable of output powers in the range of 50 to 230 W. The problems encountered by the RF output network in handling the power of many such channels are discussed. The importance of testing is stressed, and illustrations are drawn in particular from earlier work on the former COMSAT (STC) direct broadcast TV satellite. It is shown that by design and careful testing, the problems of handling multicarrier signals in communications satellites up to a mean power level of 1 kW at Ku-band can be resolved using the presented techniques. The minimizing of passive intermodulation products appears to cause the most persistent development problems. The test regimens considered necessary for examining high-power components are illustrated by tests conducted on waveguide switches selected for these applications. Should higher powers be required, many lower power amplifiers can be used to advantage in a phased antenna array
Keywords :
microwave amplifiers; satellite relay systems; travelling-wave-tubes; 1 kW; 50 to 230 W; COMSAT; Ku-band; RF output network; STC; communications satellites; direct broadcast TV satellite; helix tubes; high power TWTA; high-power components; multicarrier signals; passive intermodulation products; phased antenna array; power amplifiers; spacecraft; testing; traveling wave tubes; waveguide switches; Artificial satellites; Phased arrays; Power demand; Power generation; Radio frequency; Satellite broadcasting; Signal design; Space vehicles; TV broadcasting; Testing;
Conference_Titel :
Military Communications Conference, 1990. MILCOM '90, Conference Record, A New Era. 1990 IEEE
Conference_Location :
Monterey, CA
DOI :
10.1109/MILCOM.1990.117410
