Radio Propagation Measurement and Channel Modelling

Chapter 1

Radio Wave Fundamentals

Radio wave propagation is governed by the theory of electromagnetism laid down by the Scottish physicist and mathematician James Clerk Maxwell (13 June 1831 to 5 November 1879) who demonstrated that electricity, magnetism and light are all manifestations of the same phenomenon. Electromagnetic wave propagation depends on the properties of the transmission medium in which they travel. Classifications of transmission media include linear versus nonlinear, bounded versus unbounded, homogeneous versus nonhomogeneous and isotropic versus nonisotropic. Linearity implies that the principle of superposition can be applied at a particular point, whereas a medium can be considered bounded if it is finite in extent or unbounded otherwise. Homogeneity refers to the uniformity of the physical properties of the medium at different points and an isotropic medium has the same physical properties in different directions.

In this chapter we start by a revision of the fundamentals of Maxwell's wave equations and polarization. This is followed by a discussion of the different propagation phenomena including reflection, refraction, scattering, diffraction, ducting and frequency dispersion. These are discussed in relation to different transmission media such as propagation in free space, the troposphere and the ionosphere. For a more detailed treatment of the subject, the reader is referred to [1, 2].

1.1 Maxwell's Equations

Originally Maxwell's equations referred to ...