Klystron
A klystron is a specialized vacuum tube (evacuated electron tube) used as an oscillator or amplifier at microwave frequencies to produce high-power radio signals.In the klystron, an electron beam is velocity modulated (periodically bunched) to produce large amounts of power. They can produce high frequency high amplitude signals that most solid-state devices are incapable of. They are used in radar, satellite and wideband high power communication, and high- power physics (particle accelerators).
See also: Magnetron
