Abstract: The present invention relates to a device for attenuating unwanted waves appearing in an electron tube which includes at least two coaxial cylindrical electrodes (2, 3). The electrodes (2, 3) contribute to forming the walls of a coaxial resonator. The unwanted waves to be attentuated generate surface currents in the walls of the coaxial resonator. The attenuation device includes several electrically conducting resistive elements (10) inserted into at least one wall of the resonator and arranged so as to cut the surface currents.

Abstract: Disclosed is a multistage electron collector for electron tubes. This collector comprises an imperviously sealed envelope subjected to vacuum with an input wall and a back. Within, there is a succession of electrodes and dielectric spacers. Two successive electrodes are insulated by a spacer of a first type in contact with the two electrodes and having no contact with the envelope. A spacer of a second type is in contact firstly with the electrode closest to the back and secondly with the back. Application to electron tubes, especially millimeter travelling wave tubes.

Abstract: A resonant cavity (49) which facilitates coupling to another resonant cavity includes walls (40, 42) and an electrically conducting mast (43). One of the walls (40) has a coupling orifice (41) for coupling the resonant cavity (49) to another resonant cavity. The electrically conducting mast (43) projects from the second wall (42) opposite the first wall (40) and faces the coupling orifice (41). The electrically conducting mast (43) terminates with a hook-shaped portion (44) which contacts an edge of the coupling orifice (41). The resonant cavity (49) is suited for applications requiring secondary output cavities coupled to inductive output tubes.