Portale di Ateneo - En.Unibs.it

Electromagnetic fields

Basic definitions, Maxwell’s equations and constitutive relations. Time harmonic fields. Wave equation, Poynting’s theorem, reciprocity theorem. Polarization of electromagnetic waves.
Plane waves
Plane wave propagation in isotropic media. Terminology and classification of plane waves. Reflection and refraction of plane waves. Reflection in multilayer structures. Total reflection and total transmission. Non homogeneous media.
Transmission lines
Uniform transmission lines. Examples: twisted pairs, coaxial cables, optical fibers.
Waves on transmission lines
Propagation constant: attenuation and phase constants. Characteristic impedance, reflection coefficient energy and power.
Impedance matching
Impedance matching: motivations and constraints. The quarter wave transformer; impedance matching with one or two stubs.
Plane wave packets
Group velocity: definition and physical meaning. Dispersion of wave packets: normal and anomalous group velocity dispersion regimes. Gaussian beams: theory of diffraction and comparison with geometrical optics. Focussing of a Gaussian beam.
Waveguides with conducting walls
Waveguides with ideal conducting walls: modes of lossless cylindrical structures. Rectangular waveguides; circular waveguides; coaxial cables. Waveguides with non ideal walls.
Dielectric waveguides
Guided modes of a slab waveguide. Modes of weakly guiding cylindrical rods. Attenuation and group velocity dispersion in optical fibers. Optical communications, fiber optic sensors and other uses of optical fibers.
Fundamentals of antenna theory
Equivalent dipole moment of an extended source. Far field approximations. Characterization of antennas: directivity, power gain, radiation resistance, effective area. Examples: short electric current element; half wavelength resonant dipole. Antenna arrays.