07941 - Electromagnetic Fields

Learning outcomes

Knowledge of macroscopic electromagnetic theory in non stationary conditions. Knowledge of basic electromagnetic propagation phenomena in sourceless, free space cases and in presence of sources: plane wave and spherical wave propagation. Basic knowlenge of emission, transmission and reception of radio signals. At the end of the course the student is able to master the basic design of single-link radio transmission systems, including simple propagation impairments such as surface reflection.The student knows the basic antenna parameters for both single-element and multi-element antennas

Course contents

Basic postulates of Maxwell’s theory. Maxwell’s Equations (ME) in integral and differential form and interpretations. Field continuity over a plane surface. Time-harmonic fields: complex vector formulation of ME. The basic theorems: Unicity and Poynting’s theorems.

Solution of the Maxwell’s problem in free space: wave equations in the time and frequency domain. Helmholtz equation and plane wave expansion of the field. Analysis of a TEM plane wave: characteristics, reflection on a perfectly conducting or dieletric surface. Guided propagation principles.

Maxwell’s problem in presence of a generic current source. The magnetic vector potential procedure. Solution in the case of a linear current element, and integral solution in the case of an extended source. The near field and the far field concepts. The radiation vector of an antenna. Far field approximations and interpretation as a spherical wave: energy conservation, attenuation with distance, local plane wave approximation.

Basic antenna characteristics: radiation pattern, gain, efficiency, directivity etc. Emission and reception: effective area and gain. Friis equation and its applications. Radio link design fundamentals.

Complementary and practical

Polarization. Visualization of the e.m. field through software tools.

Practical examples. Examples of examination written test

Readings/Bibliography

- Duplicated lecture notes

- G. Conciauro - Introduzione alle onde elettromagnetiche, Mc. Graw Hill (english version available)

- V. Rizzoli, Lezioni di Campi Elettromagnetici, Propagazione libera e antenne, Ed. Progetto Leonardo, Bologna

4. - P. Bassi et alii, "Propagazione di onde elettromagnetiche", Ed. CLUEB, 2006

Teaching methods

The teaching method is Inductive: from practical problems and experiments to theorization. Some parts are deductive

Assessment methods

The exam consists of an a written test and of an oral test. The final mark is the synthetic evaluation of both written and oral tests. It is possible to vision and discuss the written test manuscript only during the oral test. If written test average mark is insufficient (below 18 out of 30) the candidate must skip the oral exam and take the whole test again on a successive exam date.

Possible exceptions to the above mentioned rules will be considered and discussed case by case

Teaching tools

Blackboard. PC. Projector.

Didactic antenna set including generator, sample antennas, receiver and tools

Office hours

See the website of Vittorio Degli Esposti

See the website of Alessandra Costanzo