Chapter 5 - Cable-Shielding Experiments

Abstract

This chapter highlights the noise coupling with different types of cables and wiring setups and discusses about grounding, filtering, shielding, ESD, thermal noise, printed circuit board (PCB) layout rules and more. This chapter is very important for electronic design engineers because the content is too fundamental and important according to changing environment of technology. Later, two important coupling mechanisms: capacitive coupling and inductive coupling mechanism are reviewed. Capacitive coupling is the interaction of electric fields between the two wires. On the other hand, inductive coupling is the interaction of magnetic fields between the two circuits. These two mechanisms play an important role in higher frequencies and in longer distances. The capacitive coupling is the transfer of energy within an electrical network by means of the capacitance between circuit nodes. When two wires are near to each other, there is a parasitic capacitance between them. This parasitic capacitance depends on the length, distance, and geometry of the wires. Inductive coupling is very difficult to describe. The coupling between two wires can be increased by winding them into coils and placing them close together on a common axis, so the magnetic field of one coil passes through the other coil. The two coils may be physically contained in a single unit.