Abstract: A coupled cavity traveling wave tube has periodic permanent magnet (PPM) RF cavity structures, each of which has a plurality of permanent magnets placed substantially equidistant from a central axis, and which are outside the extent of a plurality of electron beam tunnels arranged substantially equidistant from the central axis and within the extents of the plurality of permanent magnets. Each coupled cavity RF structure is formed by adjacent ferrous polepieces and a cylindrical wall which is beyond the extent of one or more coupling apertures which couple RF energy from one coupled cavity structure to an adjacent RF cavity.

Abstract: Various crossed-field amplifiers (CFAs) are disclosed herein. In one embodiment, the geometry of the cathode and/or the anode reduces the velocity of the electrons as they travel near the anode drift block to increase the distribution of the electrons in the drift gap. In another embodiment, an abrupt geometric change to the cathode at the beginning or the end of the anode drift block can disperse the electrons, thereby increasing the rate of mixing and diffusion. By increasing the distribution of the electrons, the peak amplitude of spurious emissions produced by a CFA can be reduced.

Abstract: A band pass filter comprises an air filled aluminum chamber, having a lid and a cuboid resonant cavity having a central iris. At opposite end nodes of the cavity, perfect electric conductors (PECs) are provided. One is connected to a feed wire from an input at one end of the cavity. The other PEC is connected via a further feed wire to a radiator in a fabrication of solid-dielectric, lucent material. Threaded tuning projections opposite the PECs and in the iris are provided, whereby the pass band and the transmission characteristics of the filter in the pass band can be tuned to match the input impedance of the band pass filter and the wave guide to the output impedance of a microwave drive circuit (not shown). Typically the impedance will be 50?.

Abstract: A planar helix slow-wave structure with straight edge connections where the structure consists of two arrays of thin, parallel, conductors printed on top and bottom faces of a low-loss dielectric material or substrate, the conductors in the arrays printed on the top and bottom surfaces being inclined at different but symmetric pitch angles on the surface of the planar surface, the conjunction ends of the conductors on the top and bottom faces being connected by vertical conductors with circular rings with a diameter greater than the diameter of the vertical conductors to ensure proper connections between them, and a vacuum tunnel inside the planar helix structure.

Abstract: Disclosed herein is a class of mm and sub mm wavelength amplifiers and oscillators operating with miniature helical slow wave circuits manufactured using micro fabrication technology. The helices are supported by diamond dielectric support rods. Diamond is the best possible thermal conductor, and it can be bonded to the helix. The electron beam is transmitted, not through the center of the helix, but around the outside. In some configurations the RF power produced may be radiated directly from the slow wave circuit. The method of fabrication, which is applicable above 60 GHz, is compatible with mass production.

Abstract: A conventional (non-relativistic) magnetron provides megawatt-levels of power. The magnetron includes a fourteen vane slow wave structure that surrounds a fourteen turn helical cathode. An upstream coaxial waveguide is surrounded by a dish-shaped flange that accommodates a reflector chamber in communication with an upstream void and a downstream interaction chamber. The vanes of the slow wave structure are shaped to define fourteen resonant chambers therebetween with each of the resonant cavities having a wedge portion in communication with a neck portion.

Abstract: Disclosed herein is a class of mm and sub mm wavelength amplifiers and oscillators operating with miniature helical slow wave circuits manufactured using micro fabrication technology. The helices are supported by diamond dielectric support rods. Diamond is the best possible thermal conductor, and it can be bonded to the helix. The electron beam is transmitted, not through the center of the helix, but around the outside. In some configurations the RF power produced may be radiated directly from the slow wave circuit. The method of fabrication, which is applicable above 60 GHz, is compatible with mass production.

Abstract: A light source is powered by a magnetron and has a quartz crucible having a plasma void with an excitable fill, from which light radiates in use. Two aluminum attachment blocks are attached together and the block is attached to a casing of the magnetron by screws—not shown. The quartz crucible is attached to the block by a Faraday cage, in the form of a perforate metal enclosure secured at its rim to the block. An output formation of the magnetron has a conductive, copper cap fitted in electrical contact with it. The cap is extended by a copper rod. The rod extends through the blocks into a bore in the crucible for coupling microwaves from the magnetron into the crucible. An airspace is provided around the cap in the block. From the cap, the rod extends with negligible air gap in an alumina ceramic tube through the airspace and a boss of the block located in an aperture in an end wall of the block.

Abstract: Disclosed herein is a class of mm and sub mm wavelength amplifiers and oscillators operating with miniature helical slow wave circuits manufactured using micro fabrication technology. The helices are supported by diamond dielectric support rods. Diamond is the best possible thermal conductor, and it can be bonded to the helix. The electron beam is transmitted, not through the center of the helix, but around the outside. In some configurations the RF power produced may be radiated directly from the slow wave circuit. The method of fabrication, which is applicable above 60 GHz, is compatible with mass production.

Abstract: Disclosed herein is a class of mm and sub mm wavelength amplifiers and oscillators operating with miniature helical slow wave circuits manufactured using micro fabrication technology. The helices are supported by diamond dielectric support rods. Diamond is the best possible thermal conductor, and it can be bonded to the helix. The electron beam is transmitted, not through the center of the helix, but around the outside. In some configurations the RF power produced may be radiated directly from the slow wave circuit. The method of fabrication, which is applicable above 60 GHz, is compatible with mass production.

Abstract: Disclosed herein is a class of mm and sub mm wavelength amplifiers and oscillators operating with miniature helical slow wave circuits manufactured using micro fabrication technology. The helices are supported by diamond dielectric support rods. Diamond is the best possible thermal conductor, and it can be bonded to the helix. The electron beam is transmitted, not through the center of the helix, but around the outside. In some configurations the RF power produced may be radiated directly from the slow wave circuit. The method of fabrication, which is applicable above 60 GHz, is compatible with mass production.

Abstract: Electromagnetic wave oscillators each having a multi-tunnel and electromagnetic wave generating apparatuses including the electromagnetic wave oscillators are provided. The electromagnetic wave oscillator includes: a first waveguide which has a folded structure such that a path traveled by an electromagnetic wave through the first waveguide crosses an axial direction a plurality of times; an electron beam tunnel through which an electron beam passes, wherein the electron beam tunnel extends along the axial direction and crosses the first waveguide a plurality of times; and at least one auxiliary tunnel which extends parallel to the electron beam tunnel and which crosses the first waveguide a plurality of times.

Abstract: Various embodiments of a coupled cavity traveling wave tube are disclosed herein. For example, some embodiments provide a coupled cavity traveling wave tube including a plurality of core segments arranged in spaced-apart fashion to form an electron beam tunnel, a first longitudinal member adjacent the plurality of core segments alternately extending toward and receding from successive core segments, and a second longitudinal member adjacent to the plurality of core segments alternately extending toward and receding from successive core segments. The first and second longitudinal members are offset to extend toward different core segments.

Abstract: The invention relates to a microwave output transition for a high-power electron tube comprising a body (78) of tubular shape, along a longitudinal axis ZZ?, having two ends (80, 90), a passage (79) between the two ends that has internal surfaces for propagating electromagnetic waves, one of the ends (90), in the form of a circular cylindrical tube, comprising a conical internal propagation surface (130) and the other end (80), in the form of a tube of rectangular cross section, having two long sides (84, 85) and two short sides (86, 87) perpendicular to the long sides, the passage having two plane internal propagation surfaces (120, 122) parallel to the long sides (84, 85) and two other plane internal surfaces (124, 126) parallel to the short sides (86, 87). Each of the plane internal propagation surfaces (120, 122) parallel to the long sides (84, 85) is joined to the conical internal propagation surface (130) via a respective curved connecting surface (132, 133) having bidirectional radii of curvature.

Abstract: Disclosed herein is a class of mm and sub mm wavelength amplifiers and oscillators operating with miniature helical slow wave circuits manufactured using micro fabrication technology. The helices are supported by diamond dielectric support rods. Diamond is the best possible thermal conductor, and it can be bonded to the helix. The electron beam is transmitted, not through the center of the helix, but around the outside. In some configurations the RF power produced may be radiated directly from the slow wave circuit. The method of fabrication, which is applicable above 60 GHz, is compatible with mass production.

Abstract: Various crossed-field amplifiers (CFAs) are disclosed herein. In one embodiment, the geometry of the cathode and/or the anode reduces the velocity of the electrons as they travel near the anode drift block to increase the distribution of the electrons in the drift gap. In another embodiment, an abrupt geometric change to the cathode at the beginning or the end of the anode drift block can disperse the electrons, thereby increasing the rate of mixing and diffusion. By increasing the distribution of the electrons, the peak amplitude of spurious emissions produced by a CFA can be reduced.

Abstract: Various apparatuses and methods for a vacuum electronic device are disclosed herein. In one embodiment, a vacuum electronic device includes a vacuum housing, an array of slow wave structures inside the vacuum housing sharing a common electron beam tunnel, an electron beam input port at a first end of the common electron beam tunnel, and an electron beam output port at a second end of the common electron beam tunnel.

Abstract: An output window for a vacuum electron device comprises an output waveguide, an intermediate layer of dielectric material joined to the interior of the output waveguide with a vacuum-tight seal, and upper and lower layers of dielectric material spaced apart from the intermediate layer and arranged above and below, respectively, the intermediate layer in a vertical orientation of the output waveguide. The upper and lower layers including openings. Supports extend inwardly into the output waveguide and support the upper and lower layers. Pillars extend through the openings in the lower layer and support the intermediate layer. The openings in the upper and lower layers permit a venting of a region between the upper layer and the intermediate layer and a region between the lower layer and the intermediate layer during the sealing of the intermediate layer while the intermediate layer is supported by the pillars.

Abstract: Disclosed herein is a class of mm and sub mm wavelength amplifiers and oscillators operating with miniature helical slow wave circuits manufactured using micro fabrication technology. The helices are supported by diamond dielectric support rods. Diamond is the best possible thermal conductor, and it can be bonded to the helix. The electron beam is transmitted, not through the center of the helix, but around the outside. In some configurations the RF power produced may be radiated directly from the slow wave circuit. The method of fabrication, which is applicable above 60 GHz, is compatible with mass production.

Abstract: Disclosed herein is a class of mm and sub mm wavelength amplifiers and oscillators operating with miniature helical slow wave circuits manufactured using micro fabrication technology. The helices are supported by diamond dielectric support rods. Diamond is the best possible thermal conductor, and it can be bonded to the helix. The electron beam is transmitted, not through the center of the helix, but around the outside. In some configurations the RF power produced may be radiated directly from the slow wave circuit. The method of fabrication, which is applicable above 60 GHz, is compatible with mass production.

Abstract: Disclosed herein is a class of mm and sub mm wavelength amplifiers and oscillators operating with miniature helical slow wave circuits manufactured using micro fabrication technology. The helices are supported by diamond dielectric support rods. Diamond is the best possible thermal conductor, and it can be bonded to the helix. The electron beam is transmitted, not through the center of the helix, but around the outside. In some configurations the RF power produced may be radiated directly from the slow wave circuit. The method of fabrication, which is applicable above 60 GHz, is compatible with mass production.

Abstract: A voltage control apparatus used for an electron tube or a power supply apparatus includes a detecting circuit for detecting current flowing through a helix electrode, a voltage-limiting circuit for controlling a potential difference between the helix electrode and the anode electrode based on a predetermined voltage level; and a switch for switching based on an output from the detecting circuit. The switch connects the helix electrode and the anode electrode through the voltage-limiting circuit, or causes a short circuit between the helix electrode and the anode electrode.

Abstract: A traveling wave amplifier circuit to receive an RF wave and an electron sheet beam and to effect synchronized interaction therebetween. The circuit includes a wave guide having at least a first wall and a second wall opposite the first wall. The first wall and the second wall are connected to define an axis of propagation and a rectangular wave guide cross-section that is normal to the axis of propagation. The circuit further includes a plurality of first projections located on an interior surface of the first wall of the wave guide, the first projections being pitched in a direction of the axis of propagation. The circuit further includes a plurality of second projections located on an interior surface of the second wall of the wave guide, the second projections being pitched in a direction of the axis of propagation.

Abstract: Disclosed herein is a class of mm and sub mm wavelength amplifiers and oscillators operating with miniature helical slow wave circuits manufactured using micro fabrication technology. The helices are supported by diamond dielectric support rods. Diamond is the best possible thermal conductor, and it can be bonded to the helix. The electron beam is transmitted, not through the center of the helix, but around the outside. In some configurations the RF power produced may be radiated directly from the slow wave circuit. The method of fabrication, which is applicable above 60 GHz, is compatible with mass production.

Abstract: A bandpass filter comprises an air filled aluminum chamber having a lid and a cuboid resonant cavity having a central iris. At opposite end nodes of the cavity, perfect electric conductors (PECs) are provided. Threaded tuning projections opposite the PECs and in the iris are provided, whereby the pass band and the transmission characteristics of the filter in the pass band can be tuned to match the input impedance of the band pass filter and the wave guide to the output impedance of a microwave drive circuit. It is mounted on one end of the filter chamber, with an electrodeless bulb in a central cavity directed axially away from the chamber and the radiator in a further cavity set to one side of the central cavity. When the filter is driven, the wave guide resonates driving the bulb.

Abstract: There is provided a small-sized portable microwave plasma generator capable of generating plasma at atmospheric pressure with low electric power including a coaxial cable, an outer conductor, a connection conductor, and a connection member. The coaxial cable includes a first inner conductor and a dielectric material encircling the first inner conductor. The outer conductor encircles the coaxial cable. The connection conductor includes at least one gas inlet tube. The connection conductor electrically connects between the first inner conductor and the outer conductor at one end of the coaxial cable. The connection member includes a second inner conductor passing through the outer conductor and then connecting to the first inner conductor.

Abstract: A two-dimensional circuit for a traveling-wave tube for millimeter and sub-millimeter electromagnetic waves synchronously interacts with an electron beam in a vacuum electronic microwave amplifier or oscillator. The circuit is a solid body having a length along the tube axis. The solid body has an electrically conductive top section and an electrically conductive bottom section. The top section is configured with a plurality of vertical vanes having a width and height and configured parallel to each other. The bottom section is similarly configured such that when the circuit is viewed in cross section along the length, the vanes on the bottom section are staggered with respect to the vanes on the top section. The top section and the bottom section are separated from each other to define a tunnel through the solid body along the length.

Abstract: A bottom portion of a metal tape is attached to an end portion of a helix. A coaxial inner conductor for input or output of a high frequency signal is fixed by its end portion being interposed between upright surfaces of the metal tape. The metal tape is joined to the coaxial inner conductor by being laser-welded to opposite side surfaces of the coaxial inner conductor.

Abstract: The invention relates to vacuum tubes and especially to electron tubes. To produce the tube, and especially an electron collector comprising several electrodes, the electrodes are produced in the form of blocks of ceramic having a high thermal conductivity. The blocks are electrically conducting (at least on the surface). They are preferably made of an insulating ceramic such as aluminium nitride, and are made conductive over part of their surface. The conductive surface part is preferably formed by a conductive ceramic, preferably based on titanium nitride, or on similar conductive ceramic materials. Thus, increased strength, better heat dissipation and weight reduction are achieved.

Abstract: The present invention includes a waveguide for outputting radio frequency wave, a vacuum envelope provided with a slow-wave circuit, a coaxial connection part connecting the waveguide and the vacuum envelope, an insulating window member which is provided in the coaxial connection part and which hermetically seals a said of vacuum envelope and a said of waveguide, a coaxial center conductor of exterior portion with one end supported by the waveguide, and a coaxial center conductor of an interior portion with one end abutting on the slow-wave circuit and the other end connected to the coaxial center conductor of the exterior portion. The waveguide is provided with a screw part supporting the coaxial center conductor of the exterior portion movably in an axial direction of the coaxial center conductor of the exterior portion.

Abstract: A light-emitting device, includes: an emitter sealed with a gas emitting light caused by a microwave; a high frequency power supply section including a diamond SAW oscillator and outputting a high frequency signal being output from the diamond SAW oscillator to a subsequent stage; and a waveguide unit emitting the high frequency signal being input from the high frequency power supply section towards the emitter as the microwave.

Abstract: A coaxial waveguide converter circuit is provided for converting an input/output coaxial section of a traveling-wave tube to a waveguide. The circuit comprises a waveguide matching part for connecting an inner conductor of the coaxial section extending into the waveguide to a wall of the waveguide. The waveguide matching part includes a fitting hole for fitting the inner conductor thereinto, and a plurality of cantilever supports which define the fitting hole at leading end portions thereof. The leading end portions of the plurality of cantilever supports defining the fitting hole are uniformly kept in close contact with a peripheral surface of the inner conductor.

Abstract: A method and apparatus for producing a distributed plasma at atmospheric pressure. A distributed plasma can be produced at atmospheric pressure by using an inexpensive high frequency power source in communication with a waveguide having a plurality particularly configured couplers disposed therein. The plurality of particularly arranged couplers can be configured in the waveguide to enhance the electromagnetic field strength therein. The plurality of couplers have internal portions disposed inside the waveguide and spaced apart by a distance of ½ wavelength of the high frequency power source and external portions disposed outside the waveguide and spaced apart by a predetermined distance which is calculated to cause the electromagnetic fields in the external portions of adjacent couplers to couple and thereby further enhance the strength of the electromagnetic field in the waveguide. Plasma can be formed in plasma areas defined by gaps between electrodes disposed on the external portions.

Abstract: A RF amplifier includes a RF input section for receiving a RF input signal. At least one single-sided slow-wave structure is associated with the RF interaction section. An electron ribbon beam that interacts with the RF input supported by the at least one single-sided slow-wave structure so that the kinetic energy of the electron beam is transferred to the RF fields of the RF input signal, thus amplifying the RF input signal. A RF output section outputs the amplified RF input signal.

Abstract: A novel method of gating electron emission from field-emitter cathodes for radio frequency (RF) electrode guns and a novel cathode that provides a focused electron beam without the need for magnetic fields or a curved cathode surface are provided. The phase and strength of a predefined harmonic field, such as the 3rd harmonic field, are adjusted relative to a fundamental field to cause a field emission cathode to emit electrons at predefined times for the generation of high-brightness electron beams. The emission time is gated responsive to the combined harmonic and fundamental fields and the response of the FE cathode to the combined fields. A planar focusing cathode includes a selected dielectric material, such as a ceramic material, to provide an electron beam emission surface. Metal surfaces are provided both radially around and behind the dielectric material to shape the electric fields that accelerate and guide the beam from the cathode surface.

Abstract: A collector in a microwave tube has a collector electrode for capturing an electron beam radiated from an electron gun and passing through a slow wave circuit, an insulator disposed in contact with the outer peripheral surface of the collector electrode, and a radiator disposed in contact with the outer peripheral surface of the insulator, wherein the insulator, the outer diameter of the collector electrode, and the inner diameter of the radiator are tapered in the axial direction of the tube.

Abstract: Apparatus and methods provide a robust radio frequency (RF) interface for a helix-type traveling wave tube (TWT). As a vacuum device, the RF input to the TWT and the RF output from the TWT are sealed to maintain the vacuum. The disclosed robust RF interface techniques are advantageously less prone to breakage than conventional sealing techniques. In addition, configurations of the disclosed robust RF interface techniques can further exhibit relatively good impedance matches between a TWT and an associated antenna, which can reduce insertion losses and reflection losses, thereby advantageously increasing system RF output power.

Abstract: A high-power microwave generator employing a plurality of inexpensive commercial magnetron tubes cross-coupled by means of a secondary coupling path between each magnetron output pair, whereby a portion of the output energy from a first magnetron tube is injected into a second magnetron tube and a portion of the output energy from the second magnetron tube is similarly injected into the first magnetron tube. The resulting cross-injection of microwave energies brings the respective magnetron tube pair into a phase-lock sufficiently stable to permit coherent combination of their outputs for many high-power microwave applications, such as directed energy weapon systems. The magnetron phase-locking system requires no external components other than the secondary coupling paths of this invention.

Abstract: An improved Klystron device is disclosed which has opposed electrostatic (ES) magnetic field generating members which are uniformly spaced along a longitudinal axis to form an electron beam chamber. The ES magnetic field generating members produce a magnetic flux which confines an electron beam passing through the chamber when an alternating current (AC) is imposed upon the magnetic field generating members. An additional improvement includes a chamber formed from a single sheet of electron conductive metal having a ladder-like structure symmetrical about a longitudinal hinge which permits the structure to be folded about the hinge to form a suitable electron beam chamber.

Abstract: A novel method of gating electron emission from field-emitter cathodes for radio frequency (RF) electrode guns and a novel cathode that provides a focused electron beam without the need for magnetic fields or a curved cathode surface are provided. The phase and strength of a predefined harmonic field, such as the 3rd harmonic field, are adjusted relative to a fundamental field to cause a field emission cathode to emit electrons at predefined times for the generation of high-brightness electron beams. The emission time is gated responsive to the combined harmonic and fundamental fields and the response of the FE cathode to the combined fields. A planar focusing cathode includes a selected dielectric material, such as a ceramic material, to provide an electron beam emission surface. Metal surfaces are provided both radially around and behind the dielectric material to shape the electric fields that accelerate and guide the beam from the cathode surface.

Abstract: A slow wave structure for coupling RF energy with an electron beam comprises a co-propagating RF section including a plurality of pins having a uniform separation from the plane of an electron beam axis. An output aperture is positioned a half wavelength from a reflection section comprising a change in depth of the pintles, such that RF energy reflected by the change in pintle depth is added to the RF energy traveling with the electron beam. One or more rows of pintles are removed in the region of the output aperture to enhance coupling to the output aperture. The device may include a beam shaper for shaping the electron beam to surround the pintles, and the beam shaper and pintles may share common channels which are longitudinal to the electron beam axis. The slow wave structure may operate in forward and backward wave modes, and may be used in conjunction with other structures to form amplifiers and oscillators.

Abstract: A slow wave circuit (10, 110) of a traveling wave tube includes a three-dimensional conductive structure (30, 130). A dielectric film (36, 136) coats selected portions of the three-dimensional conductive structure (30, 130). An outer housing (12, 14, 112, 114) surrounds the three-dimensional conductive structure (30, 130) . The outer housing (12, 14, 112, 114) includes interior surfaces that connect with the dielectric film (36, 136). In a method for generating or amplifying microwave energy, a three-dimensional conductive structure is laser micromachined to define a selected generally periodic pattern thereon. The conductive structure is arranged inside a generally hollow barrel. An electron beam passes through the generally hollow three-dimensional structure and interacts with the conductive structure and the generally hollow barrel to generate or amplify the microwave energy.

Abstract: A traveling wave tube includes a glass or other insulating envelope having a plurality of substantially parallel glass rods supported therewithin which in turn support an electron gun, a collector and an intermediate slow wave structure. The slow wave structure itself provides electrostatic focussing of a central electron beam thereby eliminating the need for focussing magnetics and materially decreasing the cost of construction as well as enabling miniaturization. The slow wave structure advantageously includes cavities along the electron beam through which the r.f. energy is propagated, or a double, interleaved ring loop structure supported by dielectric fins within a ground plane cylinder disposed coaxially within the glass envelope.

Abstract: Insulating ceramic parts for insulating collector electrodes in a traveling wave tube and a vacuum envelope are formed in a cylindrical shape in which the central axis of the inner diameter diverges from the central axis of the outer diameter and are constructed such that holes are provided in portions of the insulating ceramic parts where the thickness in the radial direction is great, and high-voltage leads for supplying prescribed voltages to said collector electrodes from the exterior pass through these holes.

Abstract: An array of carbon nanotube electron sources to make an integrated array of RF (radio frequency) sources in a single vacuum envelope. The RF sources can be printed circuit traveling wave tubes.

Abstract: A printed circuit Traveling-Wave Tube (TWT) with a vacuum housing containing either a pair of identical meanderline slow-wave interaction circuits or a pair of multi-arm spiral slow-wave interaction circuits printed on two identical Photonic Band Gap crystal structures, and a gridded electron gun assembly. Printed on the two identical Photonic Band Gap crystal structures are electrical connections to connect the heater, cathode, grid and acceleration electrodes of the electron gun assembly to a power supply, RF input and output connectors surrounded by ground planes, a depressed collector, and a set of electrical connections to the depressed collector. Zig-zag metal spacers between the two identical Photonic Band Gap crystal structures are used to form the electron beam vacuum gap. Printed conducting metal strips on each side of the meanderline slow-wave interaction circuits are used for electrostatic focusing and to reduce beam edge effects of a sheet electron beam.

Abstract: A slow wave circuit 10, 110) of a traveling wave tube includes a three-dimensional conductive structure 30, 130). A dielectric film 36, 136) coats selected portions of the three-dimensional conductive structure 30, 130). An outer housing 12, 14, 112, 114) surrounds the three-dimensional conductive structure 30, 130) . The outer housing 12, 14, 112, 114) includes interior surfaces that connect with the dielectric film 36, 136). In a method for generating or amplifying microwave energy, a three-dimensional conductive structure is laser micromachined to define a selected generally periodic pattern thereon. The conductive structure is arranged inside a generally hollow barrel. An electron beam passes through the generally hollow three-dimensional structure and interacts with the conductive structure and the generally hollow barrel to generate or amplify the microwave energy.

Abstract: A method for constructing thermally and dimensionally stable traveling wave tube circuits having high dimensional stability, narrow tolerances, and very small size by providing a small hollow preform constructed of a desired material which is coated with a layer of photoresist material then exposed to a UV laser to form a desired pattern mask in the photoresist layer. The pattern masked preform is then etched to create a preform having a desired shape. After shaping, the photoresist coating is stripped from said shaped preform to form a traveling wave tube circuit. Optionally the travel wave tube circuit may be polished.

Abstract: Insulating ceramic parts for insulating collector electrodes in a traveling wave tube and a vacuum envelope are formed in a cylindrical shape in which the central axis of the inner diameter diverges from the central axis of the outer diameter and are constructed such that holes are provided in portions of the insulating ceramic parts where the thickness in the radial direction is great, and high-voltage leads for supplying prescribed voltages to said collector electrodes from the exterior pass through these holes.

Abstract: A method and device are provided for preventing deterioration of a cold cathode in an electron tube device that utilizes the cold cathode as an electron source. In accordance with the expression defining the beam current of the electron tube device, Ib<P&mgr;×Va3/2, where P&mgr; represents the perveance of an electron gun and Va represents a voltage impressed upon an accelerating electrode, the electric potential of the accelerating electrode or an adjacent electrode is maintained at the highest level of all electrodes in the electron tube at all times.