SG Undersea Cable System: Semiconductor Devices and Passive Components

Abstract

In this paper we describe the active devices and passive components used in the SG undersea cable system for the TAT-6 link between Green Hill, Rhode Island, and St. Hilaire de Riez, France. We explain reasons for component choice and present information about design, perfor mance, screening, and reliability. I. I N T R O D U C T I O NTraditionally, in high-reliability communication systems such as undersea telephone cables, well-established c o m p o n e n t a n d device d e signs a n d manufacturing processes are used. B u t with t h e development of the SG undersea cable system, this conservative a p p r o a c h has been challenged by t h e need for devices of higher performance. T h i s re q u i r e m e n t resulted, in some cases, in sophisticated device designs t h a t border on "state-of-the-art" concepts. For example, t h e increase in channel capacity or b a n d w i d t h requires high-frequency transistors in corporating design a n d processing features t h a t are relatively new. Nevertheless, new features were carefully evaluated so t h a t t h e y would meet t h e system reliability r e q u i r e m e n t s . In general, reliability is t h e governing criterion for t h e selection of c o m p o n e n t s a n d devices for t h e undersea cable system. T h i s concept a n d how it applies to passive components and active devices are covered in t h e following subsections: II, transistors; III, diodes; IV, gas tubes; V, resistors; VI, capacitors; a n d VII, inductors a n d transformers. E a c h subsection is complete for each component or device and covers: (t) choice and requirements, (ii) design a n d construction, (Hi) characterization a n d screening, a n d (iv) aging. 2405