Non-brazed helix TWT attained 3kW output at C-band and 600W at KU-band

The power handling capability of a helix traveling wave tube (TWT) has been enhanced by the introduction of an improved non-brazed helix. By solving some problems associated in developing a high-power helix TWT, such as stable electron beam formation, backward wave oscillation (BOW) suppression, and the enhancement of the power handling capability of the output circuit, a 6GHz- 3kW TWT and a 14GHz-600W TWT were realized. In a 6GHz TWT, RF data of power output 3kW, gain 36dB, conversion efficiency 15per cent, with a total efficiency 24per cent over the frequency range from 5.850 to 6.425GHz were attained with helix 15kV and beam current 1.3A. In a 14GHz TWT, RF data of power output 600W, gain 46dB, conversion efficiency 13per cent, with a total efficiency 26per cent over the frequency range from 14.0GHz to 14.5GHz was attained with helix voltage 11.5kV and beam current 0.4A. These tubes showed stable thermal characteristics as well as good RF characteristics.