This book describes the physical basis of microwave electronics and related topics such as
microwave vacuum and microwave semiconductor devices. It comprehensively discusses the main
types of microwave vacuum and microwave semiconductor devices their principles of action
theory parameters and characteristics as well as ways of increasing the frequency limit of
various devices up to the terahertz frequency band. Further it applies a unified approach to
describe charged particle interaction within electromagnetic fields and the motion laws of
charged particles in various media. The book is intended as a manual for researchers and
engineers as well as advanced undergraduate and graduate students.