Helix TWTs

A helix-Type delay line structure provides by far the broadest bandwidth for traveling-wave tubes. These impressive broadband capabilities are used in the four main TWT applications.

	Radar: Helix TWTs provide excellent radar performance in terms of power and/or gain variation within the band. Recent R&D work has significantly increased the peak power output of these tubes. For example, the TH 3833 offers 20 kW peak power in C band, from 5,4 to 5,9 GHz.
	Electronic countermeasures: ECM applications make full use of the broadband capabilities of helix TWT's, with typical bandwidths of 1 or even 1,5 octaves. To take just two examples: the TH 3956 microt TWT supplies a minimum of 50 W CW power in the traditional 6-18 GHz band, or 100 S CW power in the 7-11 GHz band.This micro TWT will equip the microwave power module (MPM) now being developed. Another TWT, the TH 3875, delivers a minimum of 40 W CW power in the 18-40 GHz band, and 80 W CW in the 25-33 GHz band.
	Telecommunications: the intrinsic broadband nature of helix TWT's provides excellent gain and power stability for the frequencies ussed in telecoms applications. A wide range of TWT are now available in Ka and Ehf frequency range.
	Space TWT's: Thomson Tubes Electroniques has established an unrivaled position as supplier to the space industry, building on experience that stated with the advent of space communications. The company's helix traveling wave tubes, based on proven technologies in all TWT components, satisfy the many key requirements for these applications: light, weight, wide bandwidth, available power. throughout the band, low RF distortion, high effiency, long life and exceptional reliability under all conditions. The latest spaceborne TWT's also feature improved thermal exchange, using collectors cooled by direct ratiation into space. These tubes cover the freuqency spectrum from L band to V band, and are sued in service telecoms an dearth observation satellites, as well as space probes.

The coupled-cavity traveling-wave tube is the ideal technological solution for systems requiring high peak and average RF power in an instantaneous bandwidth from 5 to 10 %.

This type of RT amplifier ist used in most surace an dairborne radars, as well as in high-power millimetric wave telecommunications systems.

Different types of 100 % -metallic RF structures are used,depending on the operating frequency and power range. Thomson Tubes Electroniques tubes reach1 MW peak0 KW average power in S band,

1kW peak00 W average power in Ka band, an 1 kW peak/10 W mean power in W band.

The instantaneous bandwidth varies from 2 to 12 %. For continuous wave operation (telecom applications), Thomson Tubes Electroniques produces amplifiers delivering 250 to 400 W in Q band (43.5 to 45.5 GHz).

Coupled-cavity TWTs feature an extremely rugged strucutre for excellent reliablity even in extreme climatic and mechanical environments.
For example, Thomson Tubes Electroniques has qualified tubes used in the radars on the Mirage 2000, Rafale and EFA fighters, the Arabel and Goalkeeper air defence systems on frigates and aircraft carriers, and in Ku and Ka band seekers for missiles.