A high-efficiency 100 to 150 W/12 GHz Helix traveling wave tube for satellite use
- Paper ID
1977-IAF-037
- author
- company
Thomson.CSF
- country
France
- year
1977
- abstract
Described in this paper is an advanced brazed-helix traveling-wave tube (TWT), with a direct-radiating collector, now under development at THOMSON-CSF for the coming class of high-powered geostationary satellites. Delivering from 100 to 150 watts of output signal power in the 11.7 to 12.5-GHz downlink band, this TWT (the TH 3579) will be eminently suitable for either direct or semi-direct TV-broadcasting from space, now under active study in W. Europe and elsewhere, or for a new class of telecommunications satellites, enabling the use of smaller, simpler and much cheaper earth stations by greatly increasing the EIRP. Presented are the main performance characteristics of this tube, which should feature an efficiency of 50 % minimum, with the possibility of somewhat exceeding that figure. With the two-stage collector, conduction-cooled TH 3569 TWT, from which the TH 3579 is derived, a measured efficiency of 48 % has already been obtained, while conserving excellent phase-shift and intermodulation chatacteristics. Although relatively short (only about 300 mm long), the TH 3579 will also have high gain, at least 55 dB