9796299 - Transmission Lines and Antennas

Knowledge and understanding:

The course aims at providing conceptual tools and techniques for the description of classical electromagnetic phenomena, with particular attention to most relevant applications in communications engineering. Moving from Maxwell equations and their simplest solutions, students are guided to understand the basics of radiation mechanisms and the propagation of electromagnetic waves in different environments.

Applying knowledge and understanding:

The course of Transmission Lines and Antennas provides students basic design tools for the analysis of guiding structures, transmission lines, antennas and simple radio-links. Moreover, the course allows students to analytically evaluate the interaction of electromagnetic waves with several electromagnetic environments (i.e., multi-layer structures, conductors, dielectrics, cold plasma etc.), according to relevant applications in communication engineering.

Making judgements:

Students will master all analyzed tools and design techniques to solve problems on electromagnetic field propagation and interaction, by considering which theoretical model is the most suitable to achieve accurate solutions.

Communication skills:

Students will be required to properly describe all fundamental concepts introduced throughout the course. Moreover, student ability to technically discuss specific course topics will be carefully evaluated.

Learning skills:

Students will be able to improve their knowledge on the theory of electromagnetic fields, both through the deepening of reference textbooks and also through papers in specialized scientific journals, as well as through new ideas offered by seminars.

The course includes theoretical lectures, laboratories, and numerical simulations. Should lectures be given in mixed or remote modes, some variations may be introduced in compliance with learning objectives and purposes stated in the course syllabus.

Differential and integral calculus in one variable and multivariable. 

Phasors and vectors. Signal and Systems Theory. 

Electrostatics and Magnetostatics. 

Techniques to analyze lumped-element circuits.

Although lecture attendance is not mandatory, it is strongly recommended.

Maxwell's equations, general principles and plane waves:

Introduction to electromagnetics and applications. ● Time-domain Maxwell equations. ● Lorentz force and continuity equation. ● Interdependence of Maxwell equations. ● Boundary conditions for electromagnetic fields. ● Frequency-domain Maxwell equations and complex notation. ● Polarization of electromagnetic fields. ● Constitutive relations. ● Electromagnetic media: non-polar and polar dielectrics, conductors, and cold, collisionless plasma. ● Poynting and uniqueness theorems. ● Solutions of Maxwell equations in Cartesian coordinates: plane waves. ● Homogeneous and inhomogeneous plane waves: classification. ● Plane wave spectrum and wavenumber domain. ● Dispersion of a wave-packet and Brillouin diagram. ● Phase and group velocities.

Transmission lines:

Guiding structures with cylindrical symmetry and metallic contour. ● TEM modes. ● Voltage and current on a transmission line. ● Telegraphers' equations in time and frequency domains. ● Solution of Telegraphers' equations. ● Reflection coefficient and VSWR. ● Impedance transformer formula. ● Termination on matched, short-circuited, open-circuited, and generic loads. ● Lossy transmission lines. ● Coaxial cable and bifilar line impedance calculation. ● Matching techniques by quarter-wavelength transformer and by stubs.

Reflection and transmission of plane waves:

Normal incidence. ● Snell-Cartesio laws. ● Fresnel coefficients for parallel (TM) and orthogonal (TE) polarizations. ● TE/TM equivalent transmission lines and formalism for planar multilayer structure analysis. ● Transmission in lossless media. ● Total transmission and total reflection. ● Transmission in lossy media: interface air-good conductor. ● Leontovich boundary condition. ● Brief overview of high-frequency approximation of EM field and elements of radiopropagation.

Radiation and antennas:

Electrodynamic potentials. ● Field radiated by an elementary electric dipole. ● Duality theorem. ● Field radiated by an elementary loop. ● Reactive and radiative near-field conditions. ● Far-field conditions. ● Field radiated by linear antennas. ● Image theorem and application to monopole antennas.

Transmitting and receiving antennas:

Fundamental parameters to characterize transmitting antennas. ● Calculation of parameters for dipole and loop antennas. ● Characterization of receiving antennas. ● Friis formula for link budget. ● Brief overview of RADAR equation and RCS. ● Brief overview of antenna noise temperature.

Laboratory and CAD:

Experimental verification of Snell laws at optical frequencies. ● Simple overview of MATLAB scripting to solve electromagnetic problems. ● Measurement of antenna radiation pattern.

Applied Electromagnetics

[1] C. A. Balanis, "Advanced Engineering Electromagnetics", Wiley.

[2] G. Franceschetti, "Campi Elettromagnetici", Bollati Boringhieri.

[3] G. Gerosa, P. Lampariello, "Lezioni di Campi Elettromagnetici", Edizioni Ingegneria 2000.

[4] J. Kong, "Electromagnetic Wave Theory", EMW Publishing, Cambridge, Massachusetts.

[5] C. G. Someda, "Electromagnetic Waves", CRC Press.

Fundamentals of Antennas:

[6] C. A. Balanis, "Antenna Theory: Analysis and Design", Wiley.

[7] F. S. Marzano, N. Pierdicca, "Fondamenti di Antenne", Carocci.

[8] S. J. Orfanidis, "Electromagnetic Waves and Antennas", vol. II (Antennas).

Oral exam on course topics and exercises.

Moreover, students are asked to solve simple exercises on course main topics.