Detailed coverage of all aspects of microwave superconductivity: fundamentals, fabrication, measurement, components, circuits, cryogenic packaging and market potential. Both a graduate-level textbook and a reference for microwave engineers. Applications (with either active or passive circuit elements) include those at both liquid-helium and liquid-nitrogen temperatures. Topics covered include wireless communications, space-based cryoelectronics, SQUIDs and SQUID amplifiers, NMR and MRI coils, accelerator cavities, and Josephson flux-flow devices.