High power microwave generation in vircaiors

Vircator as high-power microwave source has recently become an intensive area of research. It is the device in which own beams fields dominate. Iriod with reflex cathode investigated by H. Barkhausen and K. Kurz has been considered as low current analog of vircator. It is shown that such analogy is not correct, but parametric amplifier which based on triod with reflex cathode is real analog of vircator. The theory of vircator is developed for broad range of electron velocities.