Klystron
From ETHW
Background
The Klystron is a vacuum tube used to amplify small signals up to a high power levels applicable in radar, deep-space satellite communications and coherent RF power sources in applications like linear particle accelerators. Klystrons generally operate in the microwave radio frequency bands, but some applications have used Klystrons as low in frequency as 430Mhz (eg. Arecibo), 324 MHz (IHEP), and 201 MHz (Fermilab).
