Guest Editorial The Nineteenth Special Issue on High-Power Microwave and Millimeter-Wave Generation

Modern high-power microwave and millimeter-wave generation remains an active area of research and development across the globe. This is because of their broad range of applications in radar systems, particle accelerators, nuclear fusion, space-based communication systems, electromagnetic warfare, and most recently in microwave-assisted catalysis, extreme depth drilling, and virus decontamination. Advances in materials, cathodes, surface treatments, and novel interaction circuits design, along with new theory, improved modeling capability, and emerging manufacturing techniques push this technology toward new levels of peak and average microwave power, high-frequency capability and waveform agility, power handling capability, and efficiency.