ELECTROMAGNETIC

WAVE

By:

Dr. Saktioto, M.Phil

Topics

Waves in One Dimension

Electromagnetic Waves in Vacuum

Electromagnetic Waves in Matter

Absorption and Dispersion

Guided Waves

Waves in One Dimension

The Wave Equation

If it is displaced from equilibrium, the net transverse force on the segment between

Evidently, small disturbances on the string satisfy

Wave Equation

Waves in One DimensionSinusoidal Waves

Terminology

Complex Notation. In view of Euler’s Formula

Complex Wave Function Linear Combinations of sinusoidal Waves

Waves in One Dimension

Boundary Condition: Reflection and Transmission

The Incident WaveReflected Wave

Trasmitted Wave

Sinusoidal Incident Wave

Waves in One Dimension

Polarization

The wave equation for E and B

Electromagnetic Waves in Vacuum

Maxwell Equation

In Vacuum, E and B satisfies the three-

dimensional wave equation

Monochromatic Plane Waves

Electromagnetic Waves in Vacuum

Energy and Momentum in Electromagnetic Waves

Electromagnetic Waves in Vacuum

The energy flux density transported by

the fields is given by the Poynting vector

Electromagnetic fields not only

carry energy, they also carry

momentum. Momentum density

stored in the fields is:

For monochromatic plane waves propagating

in the z direction:

For monochromatic plane waves

Propagation in Linear Media

Electromagnetic Waves in Matter

Maxwell Equation

Index of refraction

Reflection and Transmission at Normal Incidence

Electromagnetic Waves in Matter

Reflected wave

Transmitted Wave

Reflection and Transmission at Oblique Incidence

Electromagnetic Waves in Matter

Incident wave

Reflected wave

Transmitted Wave

Electromagnetic Waves in Conductors

Absorption and Dispersion

According to Ohm’s law, the (free) current density in a conductor is proportional to the electric field:

Reflection at a Conducting Surface

Absorption and Dispersion

Incident wave

Reflected wave

Transmitted Wave

The Frequency Dependence of Permittivity

Absorption and Dispersion

Wave Guide

Guided Waves

TE Waves in a Rectangular Wave Guide

Guided Waves

The Coaxial Transmission Line

Guided Waves