28719 - Electromagnetic Fields T-1

Course Unit Page

SDGs

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.

Quality education Gender equality Industry, innovation and infrastructure

Academic Year 2021/2022

Learning outcomes

Understanding of basic phenomena related to free and guided propagation of electromagnetic fields and their use in telecommunication systems. Knowledge of transmission lines and antennas radiation properties.

Course contents

1. Theoretical theory of electromagnetic fields
• Field polarization. Time harmonic fields and complex vector quantities.
• Maxwell’s equations for harmonic fields.
• Boundary conditions and surface current densities. Perfect conductors.
• Main Theorems of the Electromagnetic Theory: Poynting, reciprocity, equivalence, image and uniqueness.

2. Maxwell's equation solution
Without sources
• Helmholtz equation and its solution in homogeneous media: Plane waves and their classification.
• Effect of discontinuities. Reflection and refraction. Total reflection and refraction.
With sources:
• Scalar and vector potentials.
• Radiation from a point electrical source. Radiation and near field.

3. Free Space Radio Propagation
Antennas
• Radiation vector
• Radiation properties: radiation intensity, radiation function, directivity and gain, effective area.
• Introduction to antenna array
Friis formula

4. Transmission lines
• Cylindrical structures.
• TEM modes: Basic equations
• Propagation and attenuation constants.
• Load matching
• Loaded lossless transmission lines: Voltage Standing Wave Ratio.
• Smith chart
• Impedance matching with distributed elements: single stub, quarter wavelength.

Readings/Bibliography

P.Bassi, L. Scolari, R. Zoli “Propagazione di onde elettromagnetiche”, edizioni Clueb Bologna

Fawwaz T. Ulaby - Umberto Ravaioli Fondamenti di campi elettromagnetici 8/Ed

G. Conciauro, L. Perregrini, “Fondamenti di onde elettromagnetiche”, edizioni Mc. Graw Hill

F. Morichetti, A. Melloni «Mezzi di trasmissione per l’informazione»

Sophocles J. Orfanidis, «Electromagnetic Waves and Antennas» freely available in PDF (http://eceweb1.rutgers.edu/~orfanidi/ewa/)

Teaching methods

During lecture hours, the general principles of free or guided propagation of electromagnetic fields in view of signal transmission are illustrated.

Practice hours show examples of application of the theoretical ideas illustrated during lectures. Solution of numerical exercises show how the theory can be used to solve simplified real problems.

Assessment methods

The exam consists in written teat and in a following oral part.

Once the written part is passed, the oral part takes place and concludes the exam.

The written parts aims at checking that the student can apply the studied theory solving some exercises.

The oral part aims to check the knowledge and the understanding of the general principles of the studied theory and his ability of discuss them with propriety of language

Teaching tools

Further material available at: https://virtuale.unibo.it/ (access through personal username and password).

Office hours

See the website of Marina Barbiroli

See the website of Franco Fuschini