Completely rewritten, not merely updated, High Power Microwaves, Second Edition continues to define the field of high power microwaves. It provides a unified, coherent presentation of the fundamentals in this rapidly changing field. Written from a systems perspective, the presentation is broad and introductory, with the flavor of a survey, however, it is not elementary. The authors cover the major microwave sources, their distinguishing features and primary research issues, and the fundamental limits on performance. New features include a detailed example called SuperSystem, a survey of Ultrawideband, a new class of high power radiators, and a new HPM formulary containing a compilation of frequently used rules and formulas.