Gyrotrons

Abstract The gyrotron is a vacuum tube capable of delivering high levels of radio‐frequency (RF) power at frequencies from several gigahertz to more than 500 GHz, which covers the microwave and millimeter‐wave band. Because of the structure of the RF fields in the cavity, the magnitude of the electric fields and the RF losses in the cavity walls are much lower in gyrotrons than in most microwave and millimeter‐wave vacuum tubes. As the RF frequency increases, it is not necessary to reduce the size of the cavity and output waveguide. For these reasons, the gyrotron is the principal RF device for delivering high levels of RF power at frequencies between 30 and 500 GHz.