Reflection of Electromagnetic Waves at Conductive Surfaces
Electromagnetic waves experience reflection when encountering a conductive surface. Total reflection occurs if the surface is a perfect conductor, although, in practice, a small percentage of the wave penetrates the conductor and dissipates heat. Thinner conductors may allow some wave energy to pass through to the other side. The behavior of a wave reflecting from a conductive surface resembles that of a wave traveling along a transmission line, with similarities in reflection phenomena.
In practical scenarios, a significant portion of the wave reflects, and a fraction enters the conductor, causing a net electric field at the surface. Unlike a perfect conductor, a practical conductor exhibits a nonzero electric field at its surface, indicating the entry of a portion of the incident wave. A corresponding magnetic field is present for the arriving, reflecting, and penetrating waves, resulting in surface current flow.
The ideal reflection assumes a large conductive plane perpendicular to the wave’s direction, which is seldom encountered in practice. Exceptions include vast conductive surfaces like the earth or the ocean. Practical reflections in hardware situations are intricate and often defy straightforward analysis. Analyzing simple geometries under worst-case scenarios is a practical approach, as field measurements near hardware are challenging due to the modifying impact of measuring devices on field strength.