Electromagnetic Wave Propagation I

General Foundation

The course is also offered to exchange programme students.

In brief, the understanding and familiarization with the concepts of the electromagnetic (time varying) field and the system of Maxwell equations, with the concept, properties and types of uniform plane waves (UPW), both for free space propagation and incidence onto plane interface between two homogeneous media. More specifically: • Nature of the general electromagnetic problem, as described by the system of Maxwell equations, boundary conditions and constitutive equations. General form of the sources in an electromagnetic problem. Concept of electromagnetic potentials and their relationship through the Lorentz gauge. • General equation of electromagnetic wave propagation and understanding of the approximation that leads to the wave/diffusion equation. The concept of power flow associated with any time varying electromagnetic problem, Poynting vector and theorem, understanding of the terms in the equation and of the power conservation principle. • Definition of the UPW, its origin and physical significance in the general case. Comprehension of the instantaneous value concept and the complex representation of an EEC with harmonic time variation. Approximation for UPW propagating in dielectric and conductive media, perfect or not, and familiarization with the mathematical treatment of relevant problems. Definition, physical meaning and types of UPW polarization. • Power flow associated with the UPW: Density of propagating power, Poynting vector and theorem, power loss and stored energy. Generalization to propagation in arbitrary direction and the understanding of the concept of phase velocity and wavelength along an arbitrary direction. Formulation of the problem of UPW incidence onto a flat homogeneous media plane interface and related definitions. • Study of vertical/oblique incidence problems with parallel or perpendicular polarization for the various cases of media (conductive or dielectric, perfect or not). Properties of waves generated and the corresponding power flow. Formulation of the reflection and refraction laws, the reflection and refraction coefficients and their computation through the Fresnel equations. Computation of specific incidence angles, polarization and critical. Study of the total reflection problem and of the physical meaning and properties of a not uniform plane wave. The electromagnetic field: Time varying electromagnetic field. Maxwell's equations. Constitutive equations. Boundary conditions. Conduction and dielectric displacement current. Lorentz gauge. The general wave equation. Diffusion equation. Eddy currents. Harmonic time dependence. Instantaneous value and complex representation. Helmholtz equation. Scalar electric and vector magnetic potential. Poynting vector and power flow. Poynting theorem. Uniform plane wave: Definition and origin. Instantaneous value and complex representation. Propagation of a plane wave in lossless and lossy media. Plane wave polarisation. Transmitted power density. Propagation in an arbitrary direction. Phase velocity. Reflection and refraction of a plane wave: Definitions. Incident wave. Parallel and perpendicular polarisation. Reflection law. Snell law. Fresnel equations. Brewster angle. Critical angle. Total reflection. Inhomogeneous waves. Reflection and refraction energy coefficients. Normal and oblique incidence on perfect conductors and dielectrics. In Brief the course contains: The electromagnetic field: Time varying electromagnetic field. Maxwell's equations. Constitutive equations. Boundary conditions. Conduction and dielectric displacement current. Lorentz gauge. The general wave equation. Diffusion equation. Eddy currents. Harmonic time dependence. Instantaneous value and complex representa-tion. Helmholtz equation. Scalar electric and vector magnetic potential. Poynting vector and power flow. Poynting theorem. Uniform plane wave: Definition and origin. Instantaneous value and complex repre-sentation. Propagation of a plane wave in lossless and lossy media. Plane wave po-larisation. Transmitted power density. Propagation in an arbitrary direction. Phase velocity. Reflection and refraction of a plane wave: Definitions. Incident wave. Parallel and

26-07-2013