HIGH-PERFORMANCE TRANSISTORS FOR TELEPHONE CABLE REPEATERS

This article describes the design and development of highly linear transistors for telephone cable repeater applications. The study was initially carried out with 60 MHz transmission in mine. The regional approach was widely used both for analyzing nonlinearities arising from technological parameters and calculating the classic characteristics F(max), h //2//1. . . as a function of the electrical state. A technological process making exclusive use of ion implantation as the doping method was adopted. In view of the performance characteristics achieved, a similar study was conducted for transmissions at 200 MHz. The fineness of the structures and the accuracy needing to be achieved from the geometry and doping standpoints made it necessary to develop new technological procedures. Characterization of the first transistors produced in this way shows that it is possible to develop a family having cut-off frequencies in excess of 7 Ghz and consequently suited to transmission at 200 MHz.