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.

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.

Provided are a slow wave circuit and a traveling wave tube suitable for an increase in fineness with regard to processing beam holes, and suitable for higher frequencies. A slow wave circuit (10) includes a meandering waveguide (1) and a beam hole (2) that pierces the meandering waveguide (1), and the cross-section of the beam hole (2) in the direction orthogonal to the long direction is in the shape of a polygon having a larger number of sides than a quadrilateral.

Provided are a slow wave circuit and a traveling wave tube suitable for an increase in fineness with regard to processing beam holes, and suitable for higher frequencies. A slow wave circuit (10) includes a meandering waveguide (1) and a beam hole (2) that pierces the meandering waveguide (1), and the cross-section of the beam hole (2) in the direction orthogonal to the long direction is in the shape of a polygon having a larger number of sides than a quadrilateral.

A magnetron characterized by a supporting cylinder, a field emission cathode, a slow wave structure, and a waveguide. The slow wave structure includes an anode block positioned coaxial with and surrounded by the field emission cathode. The anode block includes sixteen radially-projecting vane panels defining sixteen resonant cavities therebetween. Each of the resonant cavities may comprise a resonant channel portion positioned radially proximate to and axially coextensive with a center axis of the anode block. A void between the anode block and the field emission cathode, along with the resonant cavities, define an interaction region. The waveguide, comprising a cylinder characterized by an exterior layer surrounding an interior void, is capacitively coupled to the slow wave structure and configured to deliver radio frequency (RF) energy extracted from the interaction region by one (or, optionally, two) excitation rings mounted at a downstream end of the anode block.

A magnetron characterized by a supporting cylinder, a field emission cathode, a slow wave structure, and a waveguide. The slow wave structure includes an anode block positioned coaxial with and surrounded by the field emission cathode. The anode block includes sixteen radially-projecting vane panels defining sixteen resonant cavities therebetween. Each of the resonant cavities may comprise a resonant channel portion positioned radially proximate to and axially coextensive with a center axis of the anode block. A void between the anode block and the field emission cathode, along with the resonant cavities, define an interaction region. The waveguide, comprising a cylinder characterized by an exterior layer surrounding an interior void, is capacitively coupled to the slow wave structure and configured to deliver radio frequency (RF) energy extracted from the interaction region by one (or, optionally, two) excitation rings mounted at a downstream end of the anode block.

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.

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.

Described herein is a traveling wave tube (TWT), comprising an electron gun configured to generate an electron beam (E-beam); a signal injector configured to generate a radio frequency (RF) signal; a slow wave structure (SWS) having an aperture configured to combine the E-beam and the RF signal; an outer wall enclosing the SWS; and at least one electromagnetically-active material on one of (1) at least one projection on at least one of a periphery of the SWS and on a side of the outer wall facing the SWS and (2) the periphery of the SWS configured to receive at least one electromagnetic signal to control, on-the-fly, amplification of the RF signal by maximizing dampening of spurious modes while minimizing dampening of operating modes.

Described herein is a traveling wave tube (TWT), comprising an electron gun configured to generate an electron beam (E-beam); a signal injector configured to generate a radio frequency (RF) signal; a slow wave structure (SWS) having an aperture configured to combine the E-beam and the RF signal; an outer wall enclosing the SWS; and at least one electromagnetically-active material on one of (1) at least one projection on at least one of a periphery of the SWS and on a side of the outer wall facing the SWS and (2) the periphery of the SWS configured to receive at least one electromagnetic signal to control, on-the-fly, amplification of the RF signal by maximizing dampening of spurious modes while minimizing dampening of operating modes.