Abstract: A traveling wave tube employing a coupled-cavity type slow-wave circuit and having high gain and efficiency over a wide operating frequency band as a result of a design in which the slow-wave circuits are separated into first and second (i.e. fore) and output slow-wave circuits connected to one another by sever sections containing nonreflectivity terminated waveguides. The synchronizing frequency of one of the fore slow-wave circuits is selected to be different from that of the other fore slow-wave circuit and the output slow-wave circuit. The aforesaid slow-wave circuits incorporate coupler cavities at the opposite ends thereof and a plurality of main unit cavities positioned between the coupler cavities. The desired synchronizing frequencies are obtained by controlling the dimensions of the cavities, interaction gaps, apertures and coupling irises.

Abstract: A coupled cavity type slow-wave structure for use in a travelling-wave tube, in which there are provided at a given spacing a plurality of partition walls within a circular wave-guide, with dielectric cylindrical pieces or spacers being confined between each pair of the aforesaid partition walls and in concentric relation to central apertures defined in the aforesaid partition walls. The dielectric cylindrical pieces are provided with holes slightly larger than the aforesaid central apertures in the partition walls, and the aforesaid central apertures are adapted to pass electron beams therethrough. In addition, the partition walls each have coupling slots, through which adjoining cavities are in communication with each other. The dielectric cylindrical pieces are brazed to the adjacent partition walls in gas-tight relation.

Abstract: Shielding means for preventing the emission of microwave radiation from microwave tubes which are typically comprised of an electron gun source, an intermediate body section and a collector section electrically isolated from the adjacent body section by means of a ceramic seal. A metallic shield has one end connected to the body section (or the collector section) and has its other end spaced from the collector section (or body section). An insulation layer is interposed in the gap space between the shield and the collector section (or body section). A microwave energy-lossy body is arranged in contact with one or both sides of the insulation layer to absorb microwave radiation transmitted along the insulation layer so as to prevent emission of potentially harmful microwave energy from the tube. The insulation layer may comprise either a linear or elongated tortuous undulating path.