- Docente: Alessandro Lipparini
- Credits: 6
- SSD: ING-INF/02
- Language: Italian
- Teaching Mode: Traditional lectures
- Campus: Bologna
- Corso: First cycle degree programme (L) in Telecommunications Engineering (cod. 0046)
Learning outcomes
Development of a thorough scientific-methodological understanding of guided electromagnetic propagation. Knowledge of the principal wave-guiding structures and of their use both in telecommunications systems and in high-frequency integrated circuits (above several hundred MHz). Ability to solve analysis and design problems concerning distributed circuits and subsystems.
Course contents
Cylindrical structures as a mathematical model of wave-guiding structures. Mode concept and mode set completness. Numerable mode sets of closed structures; cutoff phenomenon. Radiation modes and radiation phenomena in open structures. Mode orthogonality and excitation of wave-guiding structures; discontinuities. Guided hybrid modes in non-homogeneous closed and open structures.
Effects of imperfect conductors and perturbative analysis of low-loss structures.
Applications: transmission lines, metallic waveguides, optical fibers.
Distorsion of modulated signals in guided-wave transmission. Non-distortion conditions. Group velocity. Application to lossy transmission lines. Distortion- and attenuation-limited guided-wave structures. Distortion effects due to multimode propagation.
Multi-wire transmission lines with homogeneous and non-homogeneous dielectric. TEM and quasi-TEM modes and their circuit description. Computation of the circuit parameters. Telegraphists' equations and equivalent circuit. Matched transmission lines and characteristic impedance. Mode orthogonality and excitation of multi-wire structures. Even and odd modes of two-wire symmetric structures. Power exchange between coupled transmission lines. One-wire transmission lines.
Electromagnetics-based approach to network theory. Physical and electrical ports, relationship between electrical ports and connecting waveguides modes. Scattering matrix and its properties. Multiport network connection, impedance level of a complex system. TEM networks and rigorous derivation of circuit theory from electromagnetic theory. Limitations of circuit theory. Impedance, admittance and chain matrices of TEM multiport networks.
Readings/Bibliography
Vittorio Rizzoli and Alessandro Lipparini, 'Propagazione elettromagnetica guidata', Esculapio-Progetto Leonardo, 2002.
Robert E. Collin, 'Field Theory of Guided Waves', IEEE Press 1991.
Teaching methods
The classroom lectures are mainly devoted to the treatment of the general aspects and of the analysis techniques of wave-guiding structures and to the explanation of their practical uses. The training hours are devoted to the study of specific structures of principal importance (transmission lines, waveguides, optical fibers) and to the solution of guided-wave problems.
Assessment methods
Discussion aimed at establishing the student's understanding of the analysis techniques and of the specific properties of the principal wave-guiding structures. Solution of problems on guided electromagnetic propagation.
Teaching tools
A dedicated textbook is available where the topics developed in the course are dealt with in detail. The classroom teaching is supported by the projection of slides containing most of the mathematical details, in order to partly waive the need for the students to take notes during the lectures.
Office hours
See the website of Alessandro Lipparini