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