Abstract: A traveling wave tube (TWT) has a slow wave structure (SWS) which is severed into two or more sections. A signal path, defined below, connects the end of an SWS section to the beginning of the following SWS section. The signal path comprises an impedance matching coupler (IMC), followed by an isolator, a variable phase shifter, and a second IMC. The aggregate band pass characteristic of the components in the signal path is chosen to reject, or strongly attenuate, all frequencies outside the desired operating frequency range of the TWT and yet pass, with minimal attenuation in the forward direction, all frequencies within the desired operating frequency range. The isolator is chosen to reject, or strongly attenuate, waves, of all frequencies, which propagate in the backward direction. The aggregate phase shift characteristic of the components in the signal path is chosen to apply signal power to the beginning of the following SWS section with the phase angle yielding maximum efficiency.

Abstract: A high-pressure sodium vapor discharge lamp which is provided with a discharge tube and an outer envelope which envelopes this tube.In accordance with the improvement there are disposed in the space between the discharge tube and the outer envelope both a capacitor and a glow discharge starter which are both in parallel with the discharge tube. Consequently an external lamp starter is superfluous. In addition the lamp base may be relatively small.

Abstract: A traveling wave device having a metallic helical core element which is ceramic coated on its peripheral surfaces to provide a heat transferring dielectric and which is in intimate peripheral contact within the body of said device, to thus provide a simplified and long-life structure having improved heat conductivity permitting greater RF output and size-weight reduction of said device; and methods for forming and coating the helices.

Abstract: A travelling-wave tube comprises a delay line section, an electron collector comprising several electrodes in a cooling chamber, one end wall of which is connected to the delay line section, the several electrodes being individually mounted on an inner wall of the cooling chamber by insulation with good heat conduction characteristics and individually electrically connected to insulated bushings in the said end wall.

Abstract: Undesired oscillations are suppressed in high-power, high-frequency, multe meanderline printed circuit traveling wave tubes. .pi. point frequency oscillations of various modes are attenuated by providing resistive coated longitudinal gaps in the ground plane conductor. The gaps permit lower radio frequency currents to propagate along the length of the line while blocking transverse currents of higher .pi. mode frequencies. The resistive coatings and spacing of the gaps control losses while permitting improved operation at the desired frequency. Increased beam current is produced at the output collector due to elimination of oscillations.

Abstract: A traveling-wave tube has a slow wave circuit consisting of a constant phase velocity section extending from the electron gun side of the tube, and a phase velocity tapering section extending from the collector side of the tube in which the phase velocity of the electromagnetic wave is lower than in the constant phase velocity section. An attenuator is located at about the center of the constant phase velocity section. The ratio of the length of the phase velocity tapering section to the distance between the end of the attenuator which faces the collector side of the tube and the electron gun side end of the phase velocity tapering section is equal to, or less than 0.4.

Abstract: Backward-wave oscillations in a helix or helix-derived traveling-wave tube re prevented by dimensioning the conductive shell surrounding the helix so that the backward-wave space harmonic of the slow-wave interaction circuit has a cutoff frequency in the vicinity of the frequency of the potential backward-wave oscillations. Lossy material is disposed between the shell and helix so that there is strong coupling between the electromagnetic field and the lossy material near the cutoff frequency of the backward-wave space harmonic.

Abstract: A coupled cavity travelling wave tube is disclosed which has a sever including a termination wedge, a sever pole piece with a drift tube and a termination cavity member defining a rectangular waveguide. Disposed in the rectangular waveguide are preformed projections which are provided so as to engage with the termination wedge, the termination wedge thereby being sandwiched between the projections and the sever pole piece.

Abstract: An improved coupled cavity type traveling wave vacuum tube of the type containing serially spaced electromagnetically coupled cavities defined in spaces between serially spaced magnetic pole pieces, each of which contains magnetic ferrule portions projecting from the pole piece walls and bordering an electron beam passage through the pole piece, an electrically conductive nonmagnetic material of high thermal conductivity lines the inner walls of the ferrule, and in which a void formed in between the front and back side walls defining each pole piece is filled with a nonmagnetic material of a high thermal conductivity characteristic positioned in a thermal conducting relationship with said lining portion whereby the ability of the tube to dissipate heat generated therewithin during operation is enhanced and the tube may thereby be operated at higher duty cycles.

Abstract: The power supply for a traveling wave tube which has a cathode, a grid, a collector and a wave structure is connected between the cathode and a reference potential while first and second capacitors connected to the power supply and interconnected by a current blocking impedance deliver current respectively to the wave structure and the collector when the tube is conducting.

Abstract: A multistage depressed collector for collecting spent electrons from an electron beam useful as an element of a microwave tube includes an evacuated region having an entrance at one end for receiving electrons, and means for establishing an essentially two-dimensional hyperbolic electrostatic focusing field within the evacuated region defined by equipotential field lines having the geometry of concave curves as viewed from said electron entrance, and a plurality of electrodes located along equipotential lines, and wherein said entrance is located asymmetrically with respect to the electrodes. The foregoing structure includes a final electrode, a plurality of intermediate electrodes, each of the intermediate electrodes having an electron beam passage therethrough, and all of said electrodes having an essentially concave geometry, as viewed from said entrance.

Abstract: Ring-and-bar slow wave electronic interaction circuits of the singly and/or doubly connected variety are supported from a surrounding conductive barrel structure via the intermediary of ceramic comb structures which extend along the slow wave circuit. The ceramic "teeth" of the comb structure are brazed at their ends to the connecting bars of the slow wave circuit to enhance thermal conduction from the circuit. The free space between the teeth avoids excessive dielectric loading of the circuit. The "spines" of the ceramic combs are brazed to the barrel to provide good thermally conductive paths from the combs to the barrel for cooling of the slow wave circuit. A microwave tube employing a doubly connected ring-and-bar circuit, supported as aforedescribed, provides a high power structure having a small signal gain bandwidth between 3.7 db points of 6 GHz at Ku band.

Abstract: A delay line for travelling-wave tubes, comprising a hollow guide with successive transversely disposed discs having elongated attenuation members which project into the interior of the hollow wave guide, with the longitudinal axes of such attenuation members extending at least approximately parallel to the longitudinal axis of the delay line and mechanically firmly supported in recesses in the transverse discs. The attenuation members are retained by a press or force fit with the transverse discs, and may be provided in the portion thereof surrounded by the associated transverse disc with at least one notch which extends transversely to the longitudinal axes of the members and which is at least partially filled with the ductile material of such associated transverse disc.

Abstract: The allowable gain of a crossed-field amplifier tube is increased by tapering the slow-wave interaction circuit to a smaller spatial period in the direction of circuit power flow. Concurrent variation of the electron beam drift velocity by tapering the dc electric or magnetic field further improves the gain and efficiency.

Abstract: Noise in reentrant-stream crossed-field amplifiers is suspected of being generated by electrons re-entering the interaction region with large amplitude cycloidal motion near the slow-wave circuit. Means to increase the electric field in a portion of the drift region preceding the circuit lowers the noise, presumably by collecting these electrons. The field may be increased by decreasing the spacing between cathode and drift electrode or by applying a bias voltage on an insulated electrode.

Abstract: A ladder shaped dielectric substrate for a meander line slow-wave structure ocated between a serpentine metallic meander line conductor and a metallic ground plane. A pair of RF connectors having respective inner conductors connected to the ends of the meander line conductor are mounted on the ground plane.

Abstract: A travelling wave tube of the kind having clover leaf cavities is provided with a periodic permanent magnetic structure, in which the magnetic material is located within noses projecting into the cavity space. A barrier between the magnetic material and the cavity space defines an evacuated envelope. Because the magnetic material is within the volume swept out by the cavity dimensions, it is positioned very close to the electron beam path.

Abstract: A delay line for traveling-wave tubes, particularly a wideband low-reflection attenuated line for millimeter waves, in the form of a hollow guide having successive transverse walls which define successive line cells, each of such walls having a central opening for the passage of the electron beam and at least one coupling opening, elongated attentuating members being disposed in the respective cells with their longitudinal axes extending parallel to the longitudinal axis of the delay line. The attenuating members are of like effective length and the matching cell lying immediately ahead of and/or behind the attenuating section of the tube contains, in each case, at least one matching member.

Abstract: A spark gap assembly of a stack of insulating plates which have on one surface thereof a pair of electrodes preassembled and affixed thereto with a defined spark gap therebetween and a piece of ionizing material disposed on and affixed to each of the plates between the pair of electrodes. The plates are stacked with mating surfaces joined together and with a center plate bearing no electrodes that is joined with mating surfaces of each of two symmetrical groups of electrode bearing plates, and an electromagnetic coil is disposed around the periphery of the center plate.

Abstract: A travelling wave tube having a periodic permanent magnetic focusing structure is provided with ferromagnetic plates having copper inserts which conduct heat away from the electron beam path and reduce the formation of hot spots.

Abstract: The magnetic field produced by the periodic permanent magnets of a travelling wave tube is shaped to improve the transmission ratio of the electron beam. The first zero magnetic field occurs within the magnet region, and the first peak magnetic field occurs at the first minima of the diameter of the electron beam.

Abstract: A traveling-wave amplifier tube adapted for use as a booster of transmitted signals has very small internal circuit attenuation so that it may be used without an electron beam as a transparent, passive path for low transmitter power. When the booster tube's beam is excited, the signal is amplified about 10dB. Upper bandedge instabilities in the lossless tube are inhibited by a lower cutoff frequency of the circuit near the output end than near the input end, so that bandedge power can flow both ways out of the large-signal output end.

Abstract: A current limiting spark gap for use in a valve type lightning or surge arrester includes a plurality of identical, mirror-image insulating gap plates assembled together to define arc elongation and cooling chambers between each pair of adjacent gap plates. Conductive electrodes are disposed on opposite sides of each gap plate. Dielectric rods extend through holes formed in the gap plates to vertically and horizontally align the gap plates in a vertical stack and to define and maintain the gap spacing between a pair of electrodes in each arc chamber. The spark gap utilizes only the electrode and arc chamber configurations to cause a follow current arc to move in each arc chamber to increase the length of the arc and to compress the arc against cooling walls and surfaces of the arc chambers. The electrode and arc chamber configurations achieve greater arc elongation and compression, and resultant cooling, to enhance follow current limitation.

Abstract: The invention relates to an arrangement comprising a traveling-wave tube mounted in a housing, and a power supply source enclosed by a separate housing.Inventively, all electrical supply lines inside the tube housing are run to a plug mounted in this housing, projecting outward and enclosed by a sleeve of electrically conductive material. The invention further provides for a central singular electrical coupling matrix in the power source, whereby all electrical connecting lines to the traveling-wave tube are combined and connected to the outside via one electrical socket carried by this housing. Both housings can easily be mounted such that, when the plug connection is established, the plug sleeve is compressed. The invention provides a space-savingly designed unit of traveling-wave tube and current supply unit connected to each other with an HF-seal.

Abstract: A travelling wave tube having cavities coupled for the fundamental mode uses a periodic permanent magnetic focussing structure. Ferromagnetic plates which carry the magnetic field to the electron beam path are provided with axial extensions adjacent to the electron beam to increase the magnetic field strength.

Abstract: A traveling wave tube has a helical delay line which is supported by a plurality of dielectric support rods extending along the delay line. The delay line and support rods are housed within a metallic sleeve which has an enlarged diameter in the area of each end of the delay line. In this area at each end of the delay line a respective coupling conductor is connected to the delay line for supplying and discharging HF energy. In order to achieve a low reflection transition between the surge impedance of the delay line and that of the coupling conductor, in the region of at least one of the two ends of the delay line, a metallic matching component is provided which is peferably spot welded to a surface formed at the diameter enlargement, the matching component including an arm which is spot welded to that surface and projections extending from the arm radially inwardly between adjacent support rods and in close proximity to the delay line.

Abstract: The klystron-resonant cavity accelerator system includes an accelerator structure having one or more sections of intercoupled resonant cavities which, with the output resonant cavity of a klystron, forms an integral rf coupled resonant cavity system for energizing the accelerator. The klystron and resonant cavity accelerator thus coupled also constitute a single evacuated system. The klystron output resonant cavity may be coupled to a resonant cavity in each of the accelerator sections by means of an energy coupling iris or by means of a intervening resonant coupling cell.

Abstract: Travelling wave tubes designed to operate interchangeably at low power cw and high pulsed power have grids to gate the pulses and to switch the peak beam current between two values. To preserve optimum beam-focus conditions, the beam diameter should be simultaneously switched. A grid covering the central region of a concave cathode draws the low-current, small beam for cw operation or the central part of a large pulsed beam. A second grid controls added pulsed emission from the surrounding annular region of te cathode. To provide the proper ratio of beam sizes and uniform cathode loading, the cathode has radially varying radius of curvature. A hyperboloid of revolution is a good shape.

Abstract: A crossed-field amplifier with a beam modulating grid for the electron gun has an auxiliary electrode which modifies the electrostatic field and thus the electron beam adjacent the entrance of the amplifier interaction space. Efficiency is improved and incidence of electrons striking the delay line is reduced.

Abstract: A coupled cavity type traveling wave tube is provided with at least one sever termination means comprising a waveguide extending outwardly from one cavity. A ceramic type attenuator is brazed to the interior surface of one thin wall of the extending waveguide. A ceramic type plate is brazed to the exterior side of the same wall whose thickness is selected to permit the thin wall to undergo plastic deformation as a result of thermal deformation of the ceramic members. An enclosure wall is provided to surround at least the ceramic type plate. The enclosure wall is capable of maintaining a vacuum condition even in the case where the thin wall may develop a leak or hole.Two sever termination means may be provided. The sever termination means may be located on the same side of the coupled cavity type structure or they may be located on the same side and share a common dividing wall, said dividing wall being the aforementioned thin, plastically deformable wall.

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: In the disclosed attenuation arrangement a plurality of axially extending boron nitride support rods having a substantially rectangular cross-section are disposed about the peripheral surface of a helical slow-wave structure. An attenuating coating is provided on the substantially radially extending opposing lateral surfaces of each rod, with the substantially circumferentially extending opposing lateral rod surfaces being free from attenuating material.

Abstract: As part of a microwave frequency device, such as a traveling wave tube, a novel slow wave structure is presented which comprises an electrically conductive wire formed into a series of interconnected loops which are spaced apart and parallel along a common axis, with said loops being arranged in alternate and intermediate pairs, the ones of said loops in said alternate pairs extending clockwise about said common axis and with the ones of said loops in said intermediate pairs extending counterclockwise about said axis and interconnecting portions of said wires joining ends of adjacent loops together to define a series electrical path which progresses from one end of the wire to the other seriatim through all said loops.

Abstract: A broad-band, low-reflection energy coupling or decoupling with a coupled cavity line in a traveling wave tube, particularly high-efficiency traveling field tubes, in which a rectangular hollow conductor is not loaded, and has the opposed walls thereof, of minimum spacing and greatest width, tapering in a direction toward the delay line, with the spacing between such walls at the delay line being approximately that between adjacent transverse walls defining respective cells of the delay line, an inductive shield being provided within the hollow conductor and spaced from the line axis, the coupling opening at the hollow conductor having an open angle larger than the corresponding angle of the coupling openings in the transverse walls of adjacent line cells.

Abstract: Selectively damped travelling wave tubes having particularly periodically alternating magnetic field for guiding the electron beam comprise a delay line consisting of cells which are separated from each other by partitions and which are positioned one behind the other in the direction of beam travel. At least one resonator chamber is provided with damping material and coupled to at least one of the cells, the resonant frequency of the resonator chamber being at least almost equivalent to a predetermined interference frequency and each of the chamber resonators formed by a recess in a partition and its resonant frequency having the most energetic oscillation corresponding at least approximately to the frequency of an interference mode which is above the operational frequency band.

Abstract: An electron beam collector for transit time tubes, in particular medium power traveling wave tubes, is electrically insulated from a housing by an intermediate layer which comprises a high-voltage resistant, temperature resistant, flexible synthetic resin sheet which is metallized on both surfaces thereof. The intermediate layer, which is not closed upon itself, encloses the electron beam collector and has edge zones which project along a surface line of the collector and which extend radially outwardly, and against each other, to form a flange. The housing includes a recess which accommodates the flange, the housing including two parts which are secured together to clamp the layer between the collector and the housing in a firm clamped fit.

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.

Abstract: An electron beam collector for transit time tubes, in particular traveling wave tubes, includes a plurality of metallic electrodes which surround the electron beam and which are spaced from one another by insulating bodies. The spacing components are firmly and preferably directly connected to the electrodes which they serve to space. The electrodes are, in each case, embraced by a sleeve which has a thermal coefficient expansion that is small in comparison to the electrodes and matched to that of the spacing components.

Abstract: A delay line for traveling wave tubes comprises a rectangular wave guide having cross members which perpendicularly protrude into the wave guide interior extending alternately from two sides facing each other of a first pair of inner wave guide walls. The wave guide inner wall includes a recess extending in the longitudinal direction of the wave guide and disposed symmetrically at both sides of the longitudinal extension of the cross members, at least in the area of their ends. Such a delay line construction provides for the provision of a magnet surrounding the line which may have a comparably small inside diameter.

Abstract: A coupled cavity traveling-wave tube is disclosed wherein each interaction cavity has an oblong configuration in a plane perpendicular to the tube axis. The oblong cavities have a length-to-width ratio of a predetermined value between about 1.2 and 1.6, preferably being about 1.5. Coupling apertures in the end walls separating adjacent interaction cavities extend circumferentially about half way around aligned circular electron beam holes along the tube axis, with the circumferential extremeties of the coupling apertures lying substantially parallel to the length of the oblong interaction cavities.

Abstract: In an electron beam generating system including a cathode, a Wehnelt electrode, an anode, three groups of at least two electrically conductive rods, the rods of each group being connected to a respective one of the cathode, the Wehnelt electrode and the anode, a plurality of electrically insulating members each holding a respective rod, and a metal disc to which the insulating members are fastened in a manner to insulate each rod from the disc and from the other rods, the disc is made in the form of a circular ring provided with a central opening and at least six additional openings disposed around the central opening, the insulating members are tubular members each having a central bore and each projecting from both sides of the disc, and each rod is inserted in the bore of a respective insulating member, and extends at least partially through, and is fastened to, its respective insulating member.

Abstract: A crossed-field device having a plurality of slow wave energy propagating structures, each with an associated cathode, requires relatively low voltage for operation to provide a high power output. Electron beam current control is achieved by means of RF drive signals. Periodic permanent magnet focusing is utilized.

Abstract: In order to reduce to a minimum the internal diameter of the focusing coils 30 of travelling-wave tubes, the electrodes of the electron gun 10 thereof terminate in cylindrical portions 26, 31 whose external surfaces are in contact, via rings 27 and 28, with metal washers 18, 19 separating insulating cylinders 14, 15, 16 stacked one on top of the other and forming a socket for the casing of the tube containing gun 10. The contact is such that the radial dimensions are minimal and high insulation can be provided between the components. Application to high-power, high-voltage travelling-wave tubes.

Abstract: A surge voltage arrester having a gas-tight housing includes a pair of electrodes arranged at a distance opposite one another and with their active surfaces facing one another. The electrodes are inserted into respective ends of a tubular insulating body which carries at least one coating of electrically conductive material on the inner surface thereof extending over a portion of the tube length, the coating of electrically conductive material defines at least the envelope of a surface whose normal is approximately at right angles to the longitudinal axis of the surface voltage arrester. The coating of electrically conductive material may be punctiform circular, oval, triangular or polygonal. The coating may also be a semiconducting material, rather than a conductive material.

Abstract: An ultra wide band traveling wave tube amplifier is disclosed. The amplifier employs a helix derived slow wave circuit arranged for electromagnetic interaction with a beam of electrons passable axially through the helix circuit. Signals to be amplified within the passband of the circuit interact with the electron stream to produce an amplified output signal which is extracted from the helix and coupled to a suitable utilization device. The bandwidth of the traveling wave tube amplifier is substantially increased by the provision of a conductive circuit loading structure disposed surrounding the helix circuit and extending for at least half of its length and preferably for substantially its entire length.

Abstract: An electron tube for use as a traveling-wave tube or the like comprises an longated housing having a central evacuated passageway therethrough and a plurality of annular magnets and circuit means supported within said housing at predetermined spaced locations along the length of said passageway within said housing. Preferably, the housing comprises a pair of generally semi-cylindrical mating ceramic substrate halves, each half including semi-annular grooves along the interior thereof which mate with respective semi-annular grooves of the other half to define annular grooves in which said magnets may be positioned or formed and annular portions of said circuit means may be deposited. Preferably, the respective ceramic substrate halves also have guide paths established therein for the reception of conductive material deposited therein to form the interconnecting portions of said circuit means.

Abstract: This invention concerns a traveling wave amplifier of pillbox configuration hat can be made for battery operation. It has a high perveance cylindrical electron gun between closely spaced, parallel, flat surfaces of a pair of thin ceramic disks sealed at their perimeters to a conductive collector ring coaxial with the electron gun. One or both of the disks support a novel planar slow wave circuit. The slow wave circuit is termed a ring-bar circuit but differs from cylindrical ring-bar structures. It includes a series of concentric conductive rings. Along one diameter of the rings, to one side of the center of the rings, the first and second, third and fourth, fifth and sixth rings, etc., are conductively connected, and to the other side of the center of the rings, the second and third, fourth and fifth, sixth and seventh rings, etc., are conductively connected.

Abstract: An electron collector for an electron beam tube, in particular a high performance transit time tube, employs a hollow member for receiving the electrons, which hollow member is surrounded by a metallic cooling sleeve which is grounded during operation of the tube and which is electrically insulated therefrom for an operating potential which deviates from the ground potential. The collector is particularly characterized in that it comprises a highly heat resistant material with a low vapor pressure (melting point at least approximately 2,000.degree.C) and apart from an insulating attachment in the area of its electron beam entry opening extends by forming a vacuum space completely free standing into the cooling sleeve. The cooling sleeve is blackened at its inner surface facing the collector and is permeated during operation by a coolant supplied from a forced cooling system.

Abstract: Within an arc extinguishing chamber are disposed a pair of main electrodes so as to cause a spark starting gap to be defined therebetween. A single auxiliary electrode is also disposed so as to cause reignition in those interspaces between the auxiliary electrode and the respective main electrodes at positions distant from said spark starting gap. Further, paths for supplying therethrough a heated gas to the reigniting spark gaps when the feet at one side of the arcs between the respective main electrodes and the auxiliary electrode have arrived at the prescribed points of the auxiliary electrode are provided.

Abstract: A method and apparatus for preventing oscillations in high-current electron guns. Spurious oscillations frequently occur as a result of interaction of the electron stream with the fields of resonant modes of the gun structure. The resonant impedances of the modes are lowered by damping with lossy dielectric or resistive materials which are suited to the high temperature and vacuum environment of electron guns. The lossy materials are located in places shielded from high electric fields applied to the gun. Lossy dielectric materials which are D.C. insulators may be used as insulating supports for gun electrodes.