Abstract: A cathode of a crossed field device includes a first electrode and a second electrode disposed about and dielectrically spaced from the first electrode. In a preferred embodiment the electrode comprises a pair of electrodes, a first one of the pair being a masking electrode disposed about and dielectrically spaced from the first electrode and a second one of the pair being an emitter electrode disposed about and dielectrically spaced from the masking electrode.

Abstract: A radio frequency amplifier having a slow wave structure supported adjacent an electron beam by a support structure. The support structure includes at least one structural support member, having a supporting rod, and a dielectric material disposed on an outer surface portion of the supporting rod. The dielectric material is different from the material of the supporting rod. More particularly the dielectric material is electrically insulating having either a resistivity which reduces upon impingement of electrons from the electron beam or a secondary emission ratio that is substantially unity. The supporting rod has high thermal conductivity and is preferably boron nitride. The dielectric material is preferably titania, magnesia or beryllia.

Abstract: Slow-wave structures are formed by the method of this invention in the form of a coupled-cavity structure. The coupled-cavity form of waveguide slow-wave structures is formed by wire electric discharge machining of disks from a solid rod of copper. The disks are supported in their desired positions by retained portions of the rod while the disks are brazed inside a cylindrical shell of copper. After brazing, the retained portions may be partially removed to form the completed slow-wave structure.