Gain- and Phase-Matched Mini-TWTs

Traveling-wave tubes (TWTs) in broadband power-combining applications should have closely matched gain and phase to achieve high system-level efficiency. A gain- and phase-matched TWT operating over a frequency band of 7.5-18 GHz with a minimum output power of 60 W is currently under production at Teledyne e2v. The tube design is based on an existing mini-TWT that incorporates focus electrode switching gun, phase velocity tapered helix slow wave structure, single-stage depressed collector, subminiature A connector at the input, and threaded Neill-Concelman connector at the output. During development and production stages, a number of devices were manufactured and their performances were matched. In this paper, we have described gain- and phase-matching techniques of such devices. Experimental results of 132 matched devices have been collated that show a gain match within ±3 dB and phase match within ±15°.