The objective of the invention is to provide a microwave tube, or the like, wherein gas adsorption action of a getter may be satisfactorily performed independently from a microwave amplification operation. In order to solve this problem, this microwave electron tube comprises: a helix wherein a microwave may progress oriented from an input section to an output section within a helical tube; an electron gun emitting an electron flow oriented toward the helix; a focusing device causing the electron flow to traverse the vicinity of the helix in the direction of a collector; the collector absorbing the electron flow; and a getter having a heater insulated from the cathode provided in the electron gun.

A folded-waveguide slow-wave structure equipped with an internal load, includes a central plate comprising a rectilinear beam tunnel of same direction as the longitudinal axis of the central plate, and a serpentine-shaped folded slit having its folds in the direction of the width of the waveguide; a lower plate and an upper plate closing the waveguide, the plates being placed on and under the central plate, respectively; at least one groove of cross section that may be variable, produced along the longitudinal axis of the waveguide, in at least one face internal to the waveguide of the lower plate, the upper plate or the central plate, and at least partially comprising a lossy material; in order to form a closed slow-wave structure through which propagates a hybrid slow wave the amplitude of which is attenuated by at least 20 dB between the start and the end of the portion of the one or more grooves containing a lossy material.

A folded-waveguide slow-wave structure equipped with an internal load, includes a central plate comprising a rectilinear beam tunnel of same direction as the longitudinal axis of the central plate, and a serpentine-shaped folded slit having its folds in the direction of the width of the waveguide; a lower plate and an upper plate closing the waveguide, the plates being placed on and under the central plate, respectively; at least one groove of cross section that may be variable, produced along the longitudinal axis of the waveguide, in at least one face internal to the waveguide of the lower plate, the upper plate or the central plate, and at least partially comprising a lossy material; in order to form a closed slow-wave structure through which propagates a hybrid slow wave the amplitude of which is attenuated by at least 20 dB between the start and the end of the portion of the one or more grooves containing a lossy material.

A self-assembling element fabricated using integrated circuit techniques may provide a small diameter helical conductor surrounding an electron beam for the construction of a vacuum electronic device such as a traveling-wave tube for terahertz scale signal.

A folded-waveguide slow-wave structure equipped with an internal load, includes a central plate comprising a rectilinear beam tunnel of same direction as the longitudinal axis of the central plate, and a serpentine-shaped folded slit having its folds in the direction of the width of the waveguide; a lower plate and an upper plate closing the waveguide, the plates being placed on and under the central plate, respectively; at least one groove of cross section that may be variable, produced along the longitudinal axis of the waveguide, in at least one face internal to the waveguide of the lower plate, the upper plate or the central plate, and at least partially comprising a lossy material; in order to form a closed slow-wave structure through which propagates a hybrid slow wave the amplitude of which is attenuated by at least 20 dB between the start and the end of the portion of the one or more grooves containing a lossy material.

A slow-wave circuit comprises: a waveguide comprising a meander-shaped part that transmits an electromagnetic wave and alternately repeats a first folded part and a second folded part folded onto the opposite side to the first folded part; and a beam hole that transmits an electron beam, extends in a predetermined direction, and penetrates the meander-shaped part, wherein the beam hole penetrates the meander-shaped part so that a part of the beam hole protrudes from the first folded part.

According to embodiments of the present invention, an electron device is provided. The electron device includes a support substrate, a conductive planar slow-wave structure on the support substrate, the conductive planar slow-wave structure being adapted to receive an electromagnetic wave signal for interaction with an electron beam, and a dielectric layer arrangement in between the conductive planar slow-wave structure and the support substrate, the dielectric layer arrangement being arranged on the support substrate at only one or more support substrate portions overlapping with the conductive planar slow-wave structure. According to further embodiments of the present invention, a method for manufacturing an electron device is also provided.

According to embodiments of the present invention, an electron device is provided. The electron device includes a support substrate, a conductive planar slow-wave structure on the support substrate, the conductive planar slow-wave structure being adapted to receive an electromagnetic wave signal for interaction with an electron beam, and a dielectric layer arrangement in between the conductive planar slow-wave structure and the support substrate, the dielectric layer arrangement being arranged on the support substrate at only one or more support substrate portions overlapping with the conductive planar slow-wave structure. According to further embodiments of the present invention, a method for manufacturing an electron device is also provided.

A travelling-wave tube includes an input apparatus, a control circuit, an electron gun, a slow-wave circuit, and an output apparatus. The input apparatus may be configured to receive a radio frequency signal, and feed the radio frequency signal into the slow-wave circuit. The control circuit may be configured to determine a quantity N of electron beams and currents of the N electron beams, and control the electron gun to emit the N electron beams. Further, the slow-wave circuit may perform beam-wave interaction with the N electron beams, to amplify power of the radio frequency signa, and because the slow-wave circuit works in a saturation region, electronic efficiency of the travelling-wave tube can be greater than or equal to a first threshold. The output apparatus may output an amplified radio frequency signal.

Electroplated helical conductors and methods for making the electroplated helical conductors are provided. The electroplated helical conductors are made from pre-formed thermally and electrically conducting nanomembrane ribbons having non-helical or helical configurations. The dimensions and shapes of the pre-formed nanomembrane ribbons are altered and controlled by the electrodeposition of a metal film onto the surfaces of the nanomembrane ribbons.