Mini-TWT in gain and phase matched applications

A gain and phase matched traveling wave tube (TWT) e2v-GPMT operating over a band of 7.5-18GHz with a minimum output power of 60W is presently under production at e2v. The present design is based on an existing mini-TWT that incorporates a focus electrode switching gun, a phase velocity tapered helix slow wave structure, a single stage depressed collector, an SMA input and a TNC output connector. During development and pre-production stages a number of tubes were manufactured and their performances were matched. In this paper we have described gain and phase matching techniques of such devices. Experimental results of a number of matched devices have been collated that show a gain match within ±3dB and phase match within ±15°.