Means for generating microwaves

Means for generating microwaves, consisting of a coaxial virtual cathode oscillator having an outer cylindrical tube, which forms a cathode and is connected to a transmission line for feeding the cathode with voltage pulses, and an inner cylindrical tube is that is at least partially transparent for electrons forms an anode and is connected to a waveguide for outputting microwave radiation generated by the formation of a virtual cathode inside a region enclosed by the anode, the cylindrical tube of the cathode on the inside with a first electrically conductive structure transversely is fitted to the longitudinal direction of the tube at a distance from the at least partially transparent to the electron tube of the anode, and that the at least partially permeable to the electron tube of the anode on the outside with a second electrically conductive structure transversely is fitted to the longitudinal direction of the tube at a distance from the cylindrical tube of the cathode to form resonant cavities in the virtual cathode oscillator.