Development of 500 W Ka-band helix-TWT and 200 W Q-Band helix-TWT for communications applications

L-3 ETI is continuing development of high power mm-wave helix-TWTs for next generation military satellite systems and broadband commercial satellite systems. In 2004 L-3 ETI developed the 8925H and demonstrated its power handling capability of 200 W at Q-Band. In 2006 L-3 ETI developed the model 8926H, a 400 W Ka-Communications-Band helix-TWT, and later increasing itpsilas power handling capability to 500 W, as reported in 2007. During 2007, using L-3 ETI IR&D funding, two more engineering units of the 500 W TWTs were built and tested with the result that the 8926HB model TWT is now ready for production. This paper discusses the latest development efforts and performance testing for the 500 W Ka-Band and 200 W Q-Band TWTs.