Electromagnetic Wave Lecture Notes

A set of flashcards based on lecture notes covering key concepts related to electromagnetic waves, including definitions and explanations of important terms.

Lossless Medium

A medium where there is no energy loss due to absorption or scattering.

Skin Depth

The distance into a conductor at which the current density falls to 1/e of its value at the surface.

Poynting Vector

A vector that represents the directional energy flux (the rate of energy transfer per unit area) of an electromagnetic field.

Intrinsic Impedance (η)

The ratio of the electric field to the magnetic field in a wave traveling in a medium, indicating how much resistance is experienced by the wave.

Power Density (P)

The amount of power per unit area carried by a wave, typically measured in watts per square meter (W/m²).

Time-Averaged Power Density (Sav)

The average power density over a period of time, often calculated for varying electromagnetic fields.

Conducting Medium

A medium with finite conductivity that supports the flow of electric current.

Attenuation Constant (α)

The measure of the rate at which a signal decreases in strength as it propagates through a medium.

Phase Velocity (up)

The speed at which a wave phase propagates in a medium.

Displacement Current Density (Ja)

The equivalent current density due to the time-varying electric field in a dielectric, related to the change in electric field over time.

Electric Field (E)

A field around charged particles that exerts a force on other charges, measured in volts per meter (V/m).

Magnetic Field (H)

A field around magnetic materials and electric currents that exerts a force on other magnetic materials and currents.

Phase Constant (β)

The constant that describes the phase shift of the wave in radians per unit distance.

Transverse Electromagnetic (TEM) Wave

An electromagnetic wave where both electric and magnetic field components are perpendicular to the direction of wave propagation.

Wave Propagation

The manner in which waves travel through a medium.

Electromagnetic Wave

A wave of oscillating electric and magnetic fields that travels through space.