This edition aims to expand the on the first edition and take the reader through to the wave equation on coaxial cable and free-space by using Maxwell’s equations. The new chapters will include time varying signals and fundamentals of Maxwell's equation. This book will introduce and discuss electromagnetic fields in an accessible manner. The author explains electroconductive fields and develops ideas relating to signal propagation and develops Maxwell’s equations and relates them to propagation in a planar optical waveguide. The first of the new chapters will introduce the idea of a travelling wave by considering the variation of voltage along a coaxial line. This concept will be used in the second new chapter which will solve Maxwell’s equations in free-space and apply them to a planar optical waveguide. As this is an area that most students find difficult, it will link back to the earlier chapters to aid understanding. This book is intended for first and second year electrical and electronics undergraduates, and can also be used for undergraduates in mechanical engineering, computing and physics. The book will include examples and homework problems.