Microfabrication of high-frequency vacuum electron devices

Advances in manufacturing technology for microstructures are allowing new opportunities for vacuum electron devices producing radio-frequency (RF) radiation. Specifically, the capability to produce small circuit structures is allowing development of RF devices at frequencies impractical with traditional machining technology. This is generating increased interest in applications in the submillimeter and terahertz frequency range. High-power RF devices in this frequency range are needed for medical, communications, defense, and homeland security applications. This paper describes the most promising microfabrication techniques applicable to high-frequency RF devices and examples of recent applications.