Electromagnetic Wave

1. ELECTROMAGNETIC
WAVE
By:
Dr. Saktioto, M.Phil

2. Topics
Waves in One Dimension
Electromagnetic Waves in Vacuum
Electromagnetic Waves in Matter
Absorption and Dispersion
Guided Waves

3. 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

4. Waves in One Dimension
Sinusoidal Waves
Terminology
Complex Notation. In view of Euler’s Formula
Complex Wave Function Linear Combinations of sinusoidal Waves

5. Waves in One Dimension
Boundary Condition: Reflection and Transmission
The Incident Wave
Reflected Wave
Trasmitted Wave
Sinusoidal
Incident Wave

6. Waves in One Dimension
Polarization

7. The wave equation for E and B
Electromagnetic Waves in Vacuum
Maxwell
Equation
In Vacuum, E and B satisfies the three-
dimensional wave equation

8. Monochromatic Plane Waves
Electromagnetic Waves in Vacuum

9. 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

10. Propagation in Linear Media
Electromagnetic Waves in Matter
Maxwell Equation
Index of refraction

11. Reflection and Transmission at Normal Incidence
Electromagnetic Waves in Matter
Reflected wave
Transmitted Wave

12. Reflection and Transmission at Oblique Incidence
Electromagnetic Waves in Matter
Incident wave
Reflected wave
Transmitted Wave

13. 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:

14. Reflection at a Conducting Surface
Absorption and Dispersion
Incident wave
Reflected wave
Transmitted Wave

15. The Frequency Dependence of Permittivity
Absorption and Dispersion

16. Wave Guide
Guided Waves

17. TE Waves in a Rectangular Wave Guide
Guided Waves

18. The Coaxial Transmission Line
Guided Waves