This book represents the substance of a course of lectures I gave during the winter of 1964 at the California Institute of Technology. In these lectures I expounded a number of newly important topics in the theory of electromagnetic wave propagation and antennas, with the purpose of presenting a coherent account of the subject in a way that would reveal the inherent simplicity of the basic ideas and would place in evidence their logical development from the Maxwell field equations. So enthusiastically were the lectures received that I was encouraged to put them into book form and thus make them available to a wider audience.
