OBIETTIVI FORMATIVI

Il corso si propone di fornire le competenze sulla propagazione elettromagnetica guidata necessarie sia alla comprensione del funzionamento che alla progettazione dei circuiti operanti in alta frequenza.

MODALITA' DIDATTICHE

Le lezioni e gli esercizi sono svolti dal docente in aula. Le esercitazioni in laboratorio sono svolte in parte dal docente e in parte dagli studenti.

PROGRAMMA/CONTENUTO

• Course organization, motivation and applications (1; 1)
• Introduction to guided propagation (1;2)
• Maxwell's equations in form suited to study mode propagation (1;3)
• Transverse components in terms of the axial components. Equations for the axial components (2;5)
• Boundary conditions on perfect electric conductors for the axial components. Conditions at dielectric interfaces for the same components (2;7)
• TEM modes and consequences on voltages and currents (2;9)
• Exercises on the calculation of TEM modes in guiding structures of interest (2;11)
• Propagation of TE and TM modes in closed and homogeneous guiding structures (3;14)
• Exercise: applications in electromagnetic compatibility (0.5;14.5)
• Considerations about group, phase, signal velocities (2;16.5)
• The effect of dielectric losses on the propagation of TE and TM modes in closed and homogeneous guiding structures (2;18.5)
• Exercises related to the modes in rectagular waveguides (1.5;20)
• Exercise: current on the wall of a WR in the presence of the fundamental mode. Slotted waveguides for measures and slot antennas (2;22)
• Circular waveguides and related applications (1;23)
• Modal vectors, voltages, currents and impedances. Fictitious transmission lines for determining the axial dependence of the modal fields in closed and homogeneous guiding structures (2;25)
• Quasi-TEM modes for inhomogeneous transmission lines (2;27)
• A few considerations on the modes of dielectric waveguides (3;30)
• Mode completeness and its consequences (2;32)
• Active power transmitted by modes through a cross-section (2;34)
• A quick analysis of resonant cavities (2;36)
• Effects of metal losses on mode propagation (2;38)
• Approximate descriptions of linear passive components: matrices S, generalized S, Z, Y (2;40)
• Common microwave components with one, two, three and four ports: simple loads, attenuators, phase shifters, insulators, overview on filters, directional couplers, circulators, hybrid junctions (4;44)
• Common applications of components: phase shifters in simple antenna arrays; circulators as duplexers; attenuators, phase shifters, directional couplers and hybrid junctions in microwave measurements (2;46)

TESTI/BIBLIOGRAFIA

• Materiale distribuito in aula
• Robert E. Collin, Foundations for microwave engineering, McGraw-Hill, 1992, New York, USA
• Robert S. Elliott, An Introduction to Guided Waves and Microwave Circuits, Prentice Hall, 1993
• Robert E. Collin, Field theory of guided waves, McGraw-Hill, 1960, New York, USA
• Fred Gardiol, Hyperfrequences, Editions Georgi, 1981, Lausanne, Switzerland
• D. Marcuse, Light transmission optics, Van Nostrand Reinhold Company, 1972, New York, USA