This work treats the essential elements of radio wave propagation without requiring recourse to advanced electromagnetic concepts and equations. However, it provides sufficient detail to allow those concerned with wireless systems to acquire quickly a practical working knowledge of the important concepts. The treatment commences with an analysis of how energy (and power) is conveyed in free space. It then examines in some detail how the proximity of the earth and the atmosphere cause the radiation traveling from a transmitter to a receiver to follow one or more of three mechanisms – the surface, sky and space waves. Radio wave propagation is placed in a practical context by considering the design aspects of communications systems at microwave frequencies. That requires an understanding of noise and its importance in systems design. Unusually, a fuller consideration of the electromagnetic properties of materials is given late in the book rather than as an introductory chapter.