Considerations in the Design of a Grounding System for a Complex Electronic Facility

Abstract

The control of unwanted coupling between potentially incompatible signals within a facility depends upon the correct design of the grounding system for that facility. The four basic noise minimization techniques associated with signal grounding that may be used to reduce unwanted coupling are described in this paper. Each technique offers certain advantages and disadvantages. However, none of the techniques individually will entirely eliminate coupling between signal circuits in most facilities. Therefore, an optimum approach to grounding would require that the best features of each of the basic techniques be used. A grounding philosophy incorporating the best features of several basic techniques in a manner appropriate for complex electronic facilities is proposed. Specifically, single-point grounding for low frequency equipments and multiplepoint grounding for high frequency equipments are recommended. Interfaces between the low frequency elements and between low frequency and high frequency elements employ the common mode rejection features of balanced lines to avoid compromising the single point portion of the grounding system.