Skin Depth and Waveguides

Abstract

The last chapter begins by asking how far electromagnetic waves penetrate into a metal and introducing the concept of skin depth. It is pointed out that this behaviour will depend both on the frequency of the waves, and whether we are considering a near-field or a far-field situation. This is followed by a treatment of waveguides and how these may be used for transporting well defined (“single mode”) electromagnetic waves in the microwave and optical region (single-mode optical fibres). The concept of a “cut-off frequency” is introduced.