Electronics Engineering | Course catalogue

ADVANCED ELECTROMAGNETICS AND SCATTERING

Course objectives

ENG GENERAL The course is aimed to present an overview of some advanced topics in Electromagnetics, of considerable importance for the applications, and an introduction to electromagnetic scattering. Key instruments extensively used for their physical intuition and representative power are the modal expansion with the relevant equivalent distributed circuits, and the plane‐wave spectra. The concepts of Green’s function and integral representation are also studied in depth. Specific • Knowledge and understanding: The course is aimed at presenting an overview of some advanced topics in Electromagnetics, of considerable importance for the applications, and an introduction to electromagnetic scattering. • Applying knowledge and understanding: Students will be able to have an overall vision of modern electromagnetics, with particular reference to the unifying methodological aspects and to the mathematical techniques employed, which will allow them to easily find their bearings in successive study or in job positions, due to the great generality of the faced themes. In particular, the students will have understood in depth the principal concepts of guided and free propagation, as well as the approach to the scattering problems, solved both in closed form (canonical problems) and numerically. • Making judgements: To be able to formulate a proper evaluation relevant to the Course topics and their importance in the applications. To be able to collect and critically evaluate additional information to achieve a greater awareness of the Course topics. • Communication skills: To be able to describe the Course topics. To be able to communicate the knowledge acquired on the Course topics. • Learning skills: Key instruments extensively used for their physical intuition and representative power are the modal expansion with the relevant equivalent distributed circuits, and the plane‐wave spectra. The concepts of Green’s function and integral representation are also studied in depth.

Channel 1

FABRIZIO FREZZA Lecturers' profile

Program - Frequency - Exams

Course program

Planar guiding structures, equivalent transmission lines for two‐dimensional waveguides. Dispersion relation, discrete spectrum of the guided modes, graphical resolution. Radiation modes, continuous spectrum. Beams with finite cross section: use of the angular spectrum, the Goos‐Hänchen shift. The transverse‐resonance method, elementary applications. Dielectric‐slab waveguides, geometrical‐optics approach. The parallel‐plate waveguide partially filled with dielectric. The non‐radiative dielectric (NRD) waveguide. The effective‐dielectric‐constant method for three‐dimensional waveguides. The slot line. The spectral‐domain method for the study of planar stratified structures. Elementary application of the method to the slot line. Recalls on dyadic algebra and analysis in electromagnetic problems. Spectral dyadic Green’s functions. Integral equations: numerical solution with the method of moments. Application of the method to the microstrip. Spectral decomposition of the fields radiated from an aperture. Asymptotic evaluation of integrals: integration by parts, the stationary‐phase method. Computation of the far field. General introduction to electromagnetic scattering and review of principal applications. Canonical problems: scattering from cylindrical and spherical structures. Recalls on Bessel and Hankel functions. Simulation of generic two‐ or three‐dimensional scatterers through arrays of cylinders or spheres. Wire‐grid modeling, Richmond method, point matching. Finite‐length wire: Pocklington and Hallen integral equations, finite‐length cylinder. Scattering in waveguides: mode‐matching method, inductive iris in rectangular waveguide. Scattering from periodic structures: Floquet’s theorem, expansions in terms of spatial harmonics, diffraction gratings. Integral representations for the electromagnetic field, integral equations for the scattering from two‐ and three‐dimensional objects of arbitrary shape: EFIE and MFIE formulations, spurious solutions, combined equations.

Prerequisites

Knowledge of the contents of the courses of mathematical analysis, general physics, circuit theory, signal theory, and basic electromagnetics.

Books

F. Frezza, Advanced Electromagnetics and Electromagnetic Scattering, freely available in pdf on the course website, 2020. Complementary material (slides, tutorial papers, notes) available on the course website. Propaedeutic material: F. Frezza, A Primer on Electromagnetic Fields, Springer, 2015.

Frequency

attendance at classes is not mandatory

Exam mode

The exam will take place by an oral test, after the end of the course and for the duration of maximum one hour, in which the questions aim at verifying the acquisition of the concepts and methodologies discussed during the lessons, with reference to the objectives, and in particular to: the understanding of the concepts transmitted during the lessons relevant to advanced electromagnetics topics of greatest relevance; the students’ capability of autonomous learning, formulating autonomous evaluations related to the importance of the treated topics in electromagnetic applications; the communication skills shown.The examination includes an oral presentation of the contents of a scientific article chosen together with the lecturer, on topics related to the course programme.

Bibliography

C.A. Balanis, Advanced engineering electromagnetic, 2nd ed., Wiley, 2012. C.A. Balanis, Antenna Theory: Analysis and Design, 4th ed., Wiley, 2016. R.C. Booton, Computational methods for electromagnetics and microwaves, Wiley, New York, 1992.

Lesson mode

The principal teaching method will be frontal lessons. Moreover, exercises are scheduled to apply the theoretical knowledge acquired. If possible, seminars and guided visits will be scheduled.