Lecturer: Marco Bressan  

Course name: Antennas and propagation
Course code: 502957
Degree course: Ingegneria Elettronica
Disciplinary field of science: ING-INF/02
University credits: CFU 9
Course website: n.d.

Specific course objectives

The aim of the course is to provide students with the basic elements for the design of radio communication links, supplying information both about the main parameters characterizing transmitting and receiving antennas and about the main phenomena of interaction between electromagnetic radiation and environment. During the course, the main class of antennas are described, particular attention is paid to practical knowledge on the antenna use, antenna performance, and on the analytical and/or numerical tools for the antenna analysis and design. The hours of practical / workshop will be spent to this end: during these hours, students can design simple antenna structures, by using dedicated software tools. Furthermore, during the course, simple models of the main phenomena of radiation-environment interaction are presented to make students able to estimate the signal to noise ratio in a radio communication link in the natural or man made environment.

Course programme

basic concepts
Transmitting antennas: radiation pattern, input parameters, directivity, gain, bandwidth, state of polarization of the radiated field, radiation from distributed sources, environmental noise. Receiving antennas: reciprocity, effective receiving cross-section, polarization loss, antenna noise temperature. Scattering: scattering cross-section, radar cross-section of a generic body; scattering properties of antennas.

Simple radiators
dipoles, loops, slots, patches, open waveguides, horns.

Aperture-type antennas
parabolic reflector antennas, aperture efficiency: illumination-, polarization-, phase-, blockage-, spillover-, surface tolerances- and losses-efficiency. Cassegrain antenna systems, offset reflector antennas.

Arrays
basic array parameters, mutual coupling, feeding networks, synthesis of the radiation pattern of uniform linear arrays, uniform two-dimensional arrays and the infinite array model.

Other types of antenna structures
possibly, general features of travelling-, surface-, leaky-wave antennas, equiangular, log-periodic antennas and/or lens antennas will be provided.

Introduction to free propagation
characteristics of the ground and structure of the earth atmosphere.

• Guided, reflected and diffracted waves by the ground surface, the radio propagation path between antennas located over a flat/spherical earth, midpath-obstacle diffraction.
• Propagation in a ionized gas in the presence of a static magnetic field, ionospheric propagation paths, minimum skip distance, maximum usable frequency.
• the refractivity of the non-ionized atmosphere, earth equivalent radius, the standard atmosphere; atmospheric ducts and non-standard refraction, slow and fast fading characteristics. tropospheric scatter propagation paths.
• Attenuation by fog, snow, rain, scattering and depolarization by rain, molecular attenuation.

Course entry requirements

Lectures require student to know the electromagnetic radiation theory, the geometrical optics and the theory and techniques for the analysis of high frequency circuits.

Course structure and teaching

Lectures (hours/year in lecture theatre): 60
Practical class (hours/year in lecture theatre): 0
Practicals / Workshops (hours/year in lecture theatre): 20

Suggested reading materials

R.E. Collin. Antennas and radiowave propagation. McGraw-Hill, 1985.

A. Paraboni. Antenne. McGraw-Hill, 1999.

A. Paraboni, M. D’Amico. Radiopropagazione. McGraw-Hill, 2002.

R. E. Collin, S. J. Zucker. Antenna Theory. McGraw-Hill, 1969. (reference book).

A. W. Rudge, K. Milne, A. D. Olver, P. Knight. The handbook of antenna design. P. Peregrinus Ltd., London, 1982. (reference book).

Testing and exams

The final test consists on a oral examination. Each student can propose a simple antenna design, realised by the tools learnt during the practical / workshop hours, as a basis for the examination discussion.