"New stages of tecnetron developments"

This report describes the result of work carried out in the course of the development of the Tecnetron, since its introduction in 1958, at the CENTRE NATIONAL D´ETUDES DES TELECOMMUNICATIONS of FRANCE. It will be recalled that the Tecnetron is a semiconductor device based on the centripetal field effect, whose characteristics are intermediate between those of vacuum-tubes and those of high-frequency transistors. The work was concerned with the possible extension of the range of the Tecnetron: by increasing its transconductance, its output power and its maximum operating frequency. It is proposed to describe and discuss: models with cylindrical neck; models, single and double, with conical neck; and models of tubular construction, with several watts dissipation, which are now in their final stages of development. These models have limiting frequencies ranging from 300 Mc/s to around 1,000 Mc/s.