# course: Electromagnetic Waves

number:
141372
teaching methods:
lecture with tutorials
media:
computer based presentation, black board and chalk
responsible person:
Prof. Dr. Ralf Peter Brinkmann
Lecturers:
Dr. Denis Eremin (ETIT), M. Sc. Michael Klute (ETIT)
language:
german
HWS:
4
CP:
5
offered in:
winter term

## dates in winter term

• start: Tuesday the 27.10.2020
• lecture Tuesdays: from 10:15 to 11.45 o'clock in Online
• tutorial Thursdays: from 10:15 to 11.45 o'clock in Online

## Exam

##### Die Angaben zu den Prüfungsmodalitäten (im WiSe 2020/2021 | SoSe 2021) erfolgen vorbehaltlich der aktuellen Situation. Notwendige Änderungen aufgrund universitärer Vorgaben werden zeitnah bekanntgegeben.

Date according to prior agreement with lecturer.

 Form of exam: oral Registration for exam: FlexNow Duration: 30min

## goals

The students learn the theory of electromagnetic waves and can solve problems in the field of high frequency technology, photonics or plasma technology.

## content

• A. Electrostatics *
• Revisit of Coulomb's law, Poisson's equation and Gauss's law; Interpretation by means of the Helmholtz decomposition theorem for vector fields
• Green's theorem, formal solution of the Poisson equation with help of the Green's function
• The Laplace equation in Cartesian and spherical coordinates and spherical functions; Green's function in spherical coordinates, multipole expansion
• B. Magnetostatics *
• Biot-Savart's law and Ampere's law; Continuity equation, vector potential and gauge transformations
• C. Electrodynamics (basics) *
• The Maxwell equations: displacement current, continuity equation; Electrodynamic potentials, gauge transformation by means of scalar calibration
• The Coulomb and Lorenz calibrations, scalar wave equation
• Green's function of the wave equation, retarded potentials
• d'Alembert solutions of the wave equation
• Conservation equations: charge, momentum and angular momentum conservation, Poynting's theorem
• Transition conditions at media boundaries and plane waves in non-conductive media; Conductive media and inhomogeneous plane waves
• D. Electrodynamics *
• Polarization of electromagnetic waves, Stokes parameters
• Revisit of the superposition principle for EM waves, phase / group velocity; Wave packets and propagation in dispersive media
• Revisit of oscillation types in waveguides; Cylindrical hollow / waveguide
• Radiation of localized oscillating sources, near and far field approximations

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## recommended knowledge

Contents of the Bachelor Lectures (PO 13) Mathematics 1, 2 and 3 as well as General Electrical Engineering 1, 2, 3 and 4

## literature

1. Panofsky, Wolfgang K. H., Phillips, Melba "Classical Electricity and Magnetism", Dover Publications Inc., 2005
2. Heald, Mark A., Marion, Jerry B. "Classical Electromagnetic Radiation", Dover Publications Inc., 1995
3. Griffiths, D.J. "Introduction to Electrodynamics", Prentice Hall, 1999
4. Jackson, John David "Klassische Elektrodynamik", Gruyter, Walter de GmbH, 1988
5. Zangwill, A. "Modern Electrodynamics", Cambridge University Press, 2013

## miscellaneous

Lectures will be held on Zoom each Tuesday starting at 10:15,

https://us02web.zoom.us/j/83966496942?pwd=aFFyRDBBc2F4Nm1JNExYNUtKV3RpZz09

Meeting ID: 839 6649 6942 Passcode: PysJD7

The mood­le cour­se for this class can be found on https://moodle.ruhr-uni-bochum.de/m/course/view.php?id=33545