500 W Ka-band helix-TWT: Transition from development to production

As part of an on-going effort to develop high-power, high-efficiency, compact millimeter-wave helix traveling-wave tubes (TWTs) for next generation military and broadband commercial satellite uplink applications, L-3 ETI has developed the 8926HB, a 500 W CW Ka-band helix-TWT, in 2007 under IR&D funding. At the end of this development phase, three key areas of improvement were identified and the necessary design adjustments were implemented in the production TWT. In late 2008, L-3 ETI has launched the first production program of the 8926HB (and the 8926HA which is a 500 W Peak / 350 W CW version) for combined orders of twenty one TWTs (QTY 16 of the 8926HB and QTY 5 of the 8926HA at this time) operating from 28 to 30 GHz. This paper discusses the performance of the production TWTs with an emphasis on the verification of the design improvements.