Abstract: According to the invention, the conducting collector wall (23) on which the electrons are collected is surrounded by a coil winding (36) which is supplied with a periodically varying current, creating a slightly divergent axial magnetic field whose amplitude is periodically variable with time. The electron trajectories strike the collector wall at a grazing, nearly tangential angle, broadening the zone of impact, and the zone of impact is swept back and forth along the length of the collector, further spreading the power to be dissipated on a greater surface of the collector. Application to realization of very high power tubes or moderate power tubes with reduced collector dimensions.

Abstract: A coupled-cavity circuit for a microwave electron tube is shown having one or more cavities whose cross-sections are polygonally shaped, such as rectangles. Located in one or more corners of the polygonally shaped cavities are irises which have a higher resonant frequency. These irises are generally triangularly shaped with rounded corners and one leg of the triangle rounded about the drift tube of the microwave electron tube.

Abstract: A crossed-field amplifier circuit of the type using a CFA tube with a slow-wave structure for the anode and the cathode, each with an input and an output terminal, and a magnetic field in the axial direction, and signals of the same frequency from a common source and of controlled phase difference and amplitude applied to the input terminals of the anode and cathode slow-wave structures whose fringing fields interact with the electron cloud between the anode and the cathode to form well defined cloud fingers which result in amplification of the input signals to provide at the output terminal of the anode an amplified signal having lower random noise than hitherto available from CFA amplifiers.

Abstract: Switching power supply for generating a voltage for a pulsating load (2), in particular for generating a helix voltage for a TWT. The switching power supply is provided with a dc voltage source (1), a buffer (12) from which the load (2) is powered, and switches (3) and a control circuit (5) for regulating the charging of the buffer from the dc voltage source (1), whereby the power supply is provided with a circuit coupled to the dc voltage source (1), which circuit consists of a current source (6), the above-mentioned switches (3) and a primary (9) of a converter (7). The buffer (12) is powered from the secondary (11) of the said converter (7). The control circuit (5) controls the switches (3) by means of a signal which is a function of the rhythm of the pulsating load and the voltage across the buffer.

Abstract: A coupled-cavity delay line for a traveling-wave tube which includes a device for focusing an electron beam along the axis of the delay line for interaction between the electron beam and an electromagnetic wave propagating along the delay line. The focusing device includes an alternate series of permanent magnets and pole pieces which confine resonant cavities on each side. Each of the pole pieces is common to a pair of adjacent cavities and is provided with a drift tube which is positioned at a center thereof and which has a central aperture for passage of the electron beam. Each of the pole pieces is also pierced by at least one intercavity coupling aperture. The delay line also comprises a heat transfer member provided in at least one of the pole pieces to extend from the drift tube to the outside of the pole piece. This heat transfer member is made of a material such as copper having a heat conductivity higher than that of a pole piece.

Abstract: A wide band device is provided for coupling between the delay line of a travelling wave tube and the external circuit transmitting the energy of the tube, comprising a coupling wave guide having a single ridge, connected on one side to the delay line and on the other being extended by one of the two ridges of the output guide, the section of the coupling guide increasing progressively, with constant impedance from the line to the output guide whereas this latter has an impedance transformer providing impedance matching between its standard guide part and the coupling guide.

Abstract: A slow-wave circuit for a TWT has periodic transverse plates extending across the axial by extending vacuum envelope. An opposed pair of apertures 24, 26 in each plate 20 couple adjacent cavities 28 between plates 20. Coupling apertures 24 in alternate plates 20 are rotated transverse to apertures 26 in the other plates to provide coupling only between adjacent cavities 28. Each plate 20 has transverse ridges 30 enclosing its axial beam aperture 22. The ridges 30 are orthogonal to the coupling apertures 24, 26 to increase beam coupling and decrease capacitance for wider bandwidth and higher impedance.

Abstract: A power supply for helix and collector electrodes of a traveling wave tube is driven by an AC power source having a frequency of at least 500 KHz. The helix supply includes plural, stacked voltage double AC to DC modules responsive to the 500 KHz source. The collector supply includes plural AC to DC modules, each having a diode full wave rectifier bridge, connected in stacked relation. Each of the modules includes a transformer with a ferrite, toroidal core dimensioned so that it is not driven into saturation by the 500 KHz source. Each module also includes inexpensive, signal switching diodes having a recovery time of approximately 4 nanoseconds. The ratio of the collector to helix DC voltages is maintained constant by threading a common lead through the apertures of the toroidal cores of the helix and collector modules. A separate common lead threaded through the apertures of the toroidal cores in the collector modules is connected directly to the 500 KHz power source.

Abstract: A horizontal deflection circuit for controlling the horizontal deflection of an electron beam in a cathode ray tube used, for example, in a video display. The circuit uses a plurality of MOSFET transistors, which are switched on and off in unison for switching between a scan mode and a retrace mode, the MOSFET transistors being cascaded to accommodate the high voltage levels which are developed during retrace. A retrace capacitor and retrace diode are connected between the source and drain terminals of each MOSFET transistor to ensure that the voltages are divided among the transistors so that the entire voltage does not appear across any single one if they do not all switch at precisely the same time.

Abstract: There is provided a miniature high gain forward wave crossed-field amplifier wherein the anode slow wave structure includes double helix coupled vanes having a predetermined pitch such that the distance between the plane of symmetry of each vane is substantially narrow as compared with the thickness of each vane. The vanes also having a predetermined length and height, the height being greater than one half of the length. The wires of the double helical coils has a cross-sectional thickness which is at least one order of magnitude less than the plane of symmetry diameter of each turn of the coils. The distance between the outer diameter of each coil along the transverse face of each vane is quite large. The pitch ratio of the vanes is less than one half of the thickness thereof. Samarium cobalt magnets are used having annular end pieces which form the walls of the vacuum chamber. A high gain of 18 to 22 dB in a volume of approximately 50 cubic inches and a weight of less than 10 pounds is achieved.

Abstract: Microwave oscillators and amplifiers which utilize a superconducting slow-wave circuit. The slow circuit is made from materials which exhibit superconductivity at relatively high critical temperatures. The slow wave circuit is integral with the device's vacuum housing. Coolant exterior to the vacuum housing maintains the circuit in the superconducting state. The slow-wave circuit, which protrudes into the vacuum housing provides modulation of an electron beam which traverses the interior of the vacuum housing. Output power is ultimately extracted from the slow wave circuit.

Abstract: A magnetically insulated transmission line oscillator employs self-generated magnetic fields to generate microwave energy. An anode of the oscillator includes slow-wave structures which are formed of a plurality of thin conductive vanes defining cavities therebetween, and a gap is formed between the anode and a cathode of the oscillator. In response to a pulsed voltage applied to the anode and cathode, self-generated magnetic fields arfe produced in a cross-field orientation with respect to the orientation of the electric field between the anode and the cathode. The cross-field magnetic fields insulate the flow of electrons in the gap and confine the flow of electrons within the gap.

Abstract: A power supply for helix and collector electrodes of a traveling wave tube is driven by an AC power source having a frequency of at least 500 KHz. The helix supply includes plural, stacked voltage doubler AC to DC modules responsive to the 500 KHz source. The collector supply includes plural AC to DC modules, each having a diode full wave rectifier bridge, connected in stacked relation. Each of the modules includes a transformer with a ferrite, toroidal core dimensioned so that it is not driven into saturation by the 500 KHz source. Each module also includes inexpensive, signal switching diodes having a recovery time of approximately 4 nanoseconds. The ratio of the collector to helix DC voltages is maintained constant by threading a common lead through the apertures of the toroidal cores of the helix and collector modules. A separate common lead threaded through the apertures of the toroidal cores in the collector modules is connected directly to the 500 KHz power source.

Abstract: A crossed-field amplifier has a cathode in the form of a P-N junction semiconductor which is biased to the conductive state to cause the crossed-field amplifier to amplify. The P and N regions of the semiconductor are connected to an energy source which is pulsed to produce conduction in the P-N junction and thereby allow secondary emission from the cathode. A reverse bias voltage prevents secondary emission from the cathode. The tube requires only low voltages to be applied to the cathode P-N junction to completely deactivate the crossed-field amplifier tube without requiring the removal of the RF drive pulse applied to the cathode- or anode-slow-wave circuit and without requiring the removal of the DC high voltage power supply which therefore need not be pulsed.

Abstract: A coupled cavity travelling wave tube has a coupling wall/ferro-magnetic pole piece formed as an iron-copper-iron sandwich with a coolant channel therein defined at least in part by the inner copper member of the sandwich. Where the coolant channel is defined also in part by a surface of an outer ferromagnetic member, at least that surface is electroplated.

Abstract: A crossed-field amplifier comprises a cylindrical array of anode circuits for broad-band high-power crossed-field operation at millimeter waves. The electric field between the cylindrical anode and the surrounding cylindrical cathode is radial and the magnetic field is axial in the space between the anode and cathode. This space is the interaction region where the power is uniformly distributed over the circumference of each cylindrical array. Power flows radially in and out of the elements of the anode circuit and also axially along the cylindrical TE.sub.01 guide within the cylindrical anode. The guide is equipped with damping elements for mode control and filter elements for controlling the overall gain, bandwidth, and stability. Because of the radial flow and axial flow of power in the amplifier, it has been termed a Radaxtron.

Abstract: A resonant cavity arranged for an electron beam to pass therethrough, is made of two spaced apart parallel substantially planar members movable with respect to each other in a direction perpendicular to their major surfaces, at least one of said members having a delay line structure on its inner face within the gap between said two members. Means are arranged for moving the members relative to each other so as to vary the spacing between said members, whereby the oscillation frequency is tuned easily. The resonant cavity can be used to realize wide-band extended interaction oscillators and klystron amplifiers.

Abstract: An improvement to an existing crossed-field amplifier is shown which includes the replacement of an existing thermionic emitter with a larger platinum emitter. The platinum emitter is cooled from a surface opposite to the surface upon which a high voltage is applied to permit the form of the existing crossed-field amplifier to be maintained.

Abstract: The cathode and tube of this invention comprise a secondary emission semiconductor cathode in a crossed-field high power amplifier. A gallium arsenide semiconductor doped with an impurity to make it more conductive than intrinsic gallium arsenide has been found to perform better than prior art secondary emission cathodes when it is incorporated as a cathode in a high-power crossed-field amplifier tube operating at high average and peak current. With a gallium arsenide cathode, the crossed-field amplifier tube exhibits a radio frequency output pulse which has fast rise time and much reduced leading-edge jitter relative to performance of the same cross-field amplifier tube having a conventional secondary emission cathode.

Abstract: A travelling-wave tube comprising a delay line in the form of a helix line which is disposed inside of a solid metal vacuum envelope. A high-performance travelling-wave tube whose delay line is distinguished by very good dissipation of the stray heat. A large bandwidth results by providing the delay line with a core of insulator material which has a metal layer at its inside and outside generated surfaces.

Abstract: A dynamic signal shaper for a cathode ray tube display system is described. In some cathode ray tubes an electromagnetic lens is driven by a correction signal derived from the beam deflection signals. The required correction signal is proportional to the product of the squares of the horizontal and vertical deflection signals. The described signal shaper incorporates means for making the constant of proportionality independently adjustable for beam deflections in each corner of cathode ray tube screen.

Abstract: A broadband transverse field interaction continuous beam amplifier device mprised of an elongated continuous cathode modulating grid structure, an elongated continuous demodulating grid-collector structure, first or input waveguide transmission line means including the modulating grid for propagating an input RF wave transversely to an electron beam traveling from the cathode-grid structure to the output-collector structure where the electrons are bunched or modulated by the process of transverse wave interaction, and second or output waveguide transmission line means including the demodulating grid for propagating an induced amplified RF output wave resulting from prebunched electrons traversing the demodulator grid. Both input and output transmission line means include slow wave structures which are implemented in the grid structures.

Abstract: In a crossed-field amplifier tube, an input section of slow-wave circuit is part of the cathode electrode. An output section of slow-wave circuit is part of the anode electrode. The anode circuit is axially displaced from the cathode circuit in the direction of drift of the electron stream so that a non-propagating section of the anode faces at least a part of the propagating cathode circuit.

Abstract: A double-coupled ladder circuit for a traveling-wave tube has been a slow-wave circuit formed of a pair of combs, each cut from a single piece of metal. Transverse grooves are cut in each piece to form teeth and axial grooves are cut in the ends of the teeth. The two combs are joined at teeth ends to form a ladder with the transverse grooves aligned to form cavities and the axial grooves aligned to form a beam passageway. Coupling apertures are cut in both sides of a first set of alternating ladder rungs and a second set of apertures cut in the comb backing members over the second, interleaved, set of rungs. Thus, each cavity is coupled on two opposite sides to its preceding cavity and on the two remaining sides to its following cavity. The double coupling provides increased bandwidth and efficiency. Finally, side plates are affixed to cover the apertures, complete the cavity walls and form the vacuum envelope.

Abstract: A generator is provided based on an interaction of the cyclotronic type between an electron beam propagating between an electron gun and a collector and a high frequency electromagnetic field in a resonating structure. It is principally characterized in that the electron beam moves along a cycloidal path in a transverse magnetic field under the effect of a drift velocity created by a continuous electric field.

Abstract: Feedback loops monitor the vertical and horizontal deflection yoke drive voltages of the CRT and separately compare each potential with a voltage which represents full screen deflection. Error voltage resulting from these comparisons adjust the power supplied the yoke to maintain full scale deflection with variations in the frequencies of the vertical sweep or horizontal sync pulses. The feedback loops can be made interdependent so that the smaller one of the two drive potentials determines the size of both drive potentials. In this way the aspect ratio will be maintained irrespective of the changes in the format presented on the screen.

Abstract: A coupled-cavity slow-wave circuit for a millimeter-wave TWT is formed by forming cavities through a metallic bar or half-cavities in a pair of comb-shaped bars. The ends of the cavities are covered by cover members, one of which has a longitudinal groove to form "in line" coupling apertures between cavities.

Abstract: A device is provided for injecting an electron beam propagating along an axis (x) in a cycloidal path under the action of a continuous electric field and a static magnetic field (B) perpendicular to the axis of propagation and to the electric field. The injection device comprises an electron gun placed in a weak magnetic field (B.sub.1) and means, placed in a magnetic field (B.sub.2) increasing progressively along the axis (x), for creating in this zone a continuous electric field having two components in the plane perpendicular to the magnetic field.

Abstract: A wide-band distributed coupler for coupling rf energy from an input waveguide into a tapered interaction waveguide in a traveling-wave amplifier comprising a plurality of channel filters connecting between the input and interaction waveguides, with each filter coupled to the interaction waveguide at the appropriate cross-sectional position along its tapered length where the interaction waveguide cutoff frequency approximately matches the wave frequency propagated by the filter. Each filter comprises, in one embodiment, a main coaxial cavity tuned to a distinct center frequency, a first simple isolation cavity for coupling rf energy between the input waveguide and the main cavity, and at least one second simple isolation cavity for coupling energy between the main cavity and the tapered interaction waveguide. This coupler is compatible both in bandwidth and geometry with the tapered interaction waveguide.

Abstract: A delay line assembly for high-performance traveling-wave tubes having an electron beam generating system and an electron beam collector, includes a copper vacuum enclosure, a delay line in the form of a ring ribbon conductor disposed in the vacuum enclosure between the electron beam generating system and the electron beam collector, and a plurality of dielectric mounting rods extended parallel to the ring ribbon conductor in the vacuum enclosure for supporting the delay line, the ring ribbon conductor being formed of a relatively more highly thermally stressed tungsten part and a relatively less highly thermally stressed molybdenum part.

Abstract: The object of the invention is to provide a traveling wave tube with increased linearity to avoid intermodulation of signals being amplified. In a traveling wave tube 10, as shown in FIG. 1, the slow wave structure is a helix (18) including a sever (21). A dynamic velocity taper is provided by gradually reducing the spacing (26) between the repeating elements of the slow wave structure which are the windings of helix (18). The reduction takes place between Zo indicated by line 23 and Z.sub.s which coincides with the output point of helix (18) as indicated by the line (22). The spacing (26) begins to decrease at Z.sub.o and is decreased by up to about 5% at Z.sub.s. The spacing (26) between the repeating elements of the slow wave structure is ideally at an exponential rate because the curve (27), as shown in FIG. 3, increases from Z.sub.o to Zs the point of maximum efficiency and power, at an exponential rate. FIG. 3 shows a coupled cavity traveling wave tube having cavities 32 through 37.

Abstract: An electron gun of the type comprising two electrodes facing each other and brought to different potentials so as to create therebetween a continuous electric field and a cathode positioned in the extension of the electrode at negative or zero potential and brought to the same potential as this latter, the assembly being subjected to a magnetic field perpendicular to the electric field. In the plane perpendicular to the magnetic field, at least one of said electrodes has a divergent profile so that the distance between electrodes increases from the cathode towards the outside of the gun.

Abstract: The invention provides a travelling wave tube comprising means for suppressing parasite oscillations and these means are formed by auxiliary helical delay lines placed inside the sleeve in the gaps between two adjacent dielectric supports, periodically fixed to the sleeve by metal supports and without contact with the main helical delay line.

Abstract: A gyromagnetron amplifier for radiation at millimeter wavelengths comprising a tapered waveguide tube with longitudinally running vanes in the walls of the tube with the number of vanes chosen to coincide with a desired cyclotron harmonic frequency to be amplified. A beam of spiralling mildly relativistic electrons with an energy of 100 keV or less is directed into the small end of the tapered waveguide tube. A tapered axial magnetic field is set up within the waveguide tube with a low value appropriate to the amplification of a cyclotron harmonic frequency. An electromagnetic wave to be amplified is launched into the waveguide tube to co-propagate and be amplified by the spiralling electron beam. This device is characterized by a wide bandwidth, a low operating magnetic field, a relatively low operating beam voltage, with high power, and the capability of continuous wave operation.

Abstract: A step waveform generator includes a cup and bucket circuit in which charging and discharging a cup capacitor (C1) with predetermined units of charge is achieved, in response to a train of pulses supplied to its input terminal (1), by means of an operational amplifier (2) continuously monitoring the voltage across the cup capacitor and alternately supplying charging current and discharging current from a first and second constant current source (I1 and I2) respectively via separate feedback loops (T3, T2 and T4, T7, T6) of the amplifier. The constant currents, or multiples or sub-multiples of the constant currents, providing each individual unit of charge, are generated by current mirrors (T8, T9, T10) and added sequentially to a bucket capacitor C2. The size of each individual step of the resultant voltage waveform derived from the bucket capacitor and appearing at output terminal 4 depends upon the combination of mirrored increments of current selected by switch (S1, S2) and added to the bucket capacitor.

Abstract: A delay line is provided for a travelling wave tube and comprising two parts:a first part formed from a delay line section comprising a central conductor mounted in a cylindrical sleeve by means of dielectric rods. This first part is situated on the high frequency input side of the tube and is focussed by means of a succession of permanent magnets with alternate orientations;a second part, following the first one which is formed from an entirely metal delay line section and which is focussed by means of a solenoid or a permanent magnet.

Abstract: A switched vertical deflection circuit derives vertical deflection current from horizontal deflection energy. A single switching element operates during both horizontal trace and retrace intervals. Conduction of the switching element is controlled by a vertical control circuit to provide the desired vertical deflection current. Feedback to the control circuit is referenced to ground potential to eliminate nonlinearity caused by voltage supply variations. The vertical circuit voltage supply is adapted to sink as well as supply current, thereby stabilizing the supply.

Abstract: A diffraction radiation generator in which a ribbon electron beam is directed over a diffraction grating within an open resonator at a selected velocity to generate coherent radiation. After passing through the open resonator, the ribbon beam is directed through aligned slits in two or more conductive elements to a collector. Progressively negative voltages relative to the grating voltage can be applied to the elements and the collector to decelerate the electrons forming the ribbon beam and thus minimize heating of the collector and increase the operating efficiency of the generator. Also, the elements and the collector can be utilized to analyze the ribbon beam.

Abstract: A wide band travelling wave amplifier including an input waveguide coaxia disposed about an interaction waveguide. Both waveguides are tapered with the same direction of increasing cross-section. The interaction waveguide is a high-pass filter while the input waveguide is a low pass filter. The input waveguide is positioned relative to the interaction waveguide so that each cutoff plane in the input waveguide corresponding to a given frequency, .omega..sub.c, is displaced in the direction of increasing cross-section from a cutoff plane in the interaction waveguide corresponding to .omega..sub.c where .omega..sub.c is any frequency in the frequency band of the amplifier. A slot, disposed between the cutoff planes corresponding to .omega..sub.c couples the .omega..sub.c frequency component of an input wave from the input waveguide to the interaction waveguide.

Abstract: There is disclosed a traveling wave tube with a slow wave structure having means for frequency and directionally sensitive wave amplification. The slow wave structure includes a conductive helix coaxially mounted within a conductive tubular housing and a conductive support structure longitudinally disposed within the housing and extending transversely from the helix to the housing. In some embodiments, the support structure is combshaped and in one embodiment is a helical ridge wound in registration with and in the same sense as the helix. The pitch of the housing and a preselected parameter of the support structure are simultaneously varied along the length of the helix such that a wave at a given frequency band traveling along the slow wave structure in a first direction is preferentially amplified with respect to waves traveling in an opposite direction.

Abstract: The rippled-field magnetron is a novel cross-field millimeter wave source in which electrons move under the combined action of a radial electric field, an axial magnetic field and an azimuthally periodic wiggler magnetic field, .vertline.B.sub.w .vertline. cos (N.theta.) oriented transversely to the flow. Estimates are given of the frequency and growth rate of the free electron laser (FEL) type of instability excited in this smooth-bore magnetron configuration.

Abstract: A tubular ring-bar slow wave structure is provided. The structure includes a plurality of axially spaced, coaxially aligned, generally parallel metallic rings connected by a plurality of generally axially parallel, alternately spaced metallic bars. The structure also includes a plurality of axially spaced, coaxially aligned, generally parallel dielectric support rings, each of which has a width that is narrower than the width of a metallic ring.

Abstract: A ladder circuit especially useful in backward wave oscillators operating in the 500 GHz to 2,000 GHz range comprises a waveguide (10) having disposed therein transversely oriented slabs (16) which contact an upper wall (22) of waveguide (10). The edges of slabs (11) adjacent the physical center of waveguide (10) along which is directed an electron beam (19) have respective curved segments (11) and stubs (12) and (13) of electrically conductive, non-magnetic material supported thereon. The ends of slabs (16) include metal layers (17) and (18) at respective opposite ends to provide a conductive leakage path. A ridge bar (20) is attached to the inside of the bottom wall (21) of the waveguide (10) and includes a concave upper surface which partially straddles electron beam (19). The inside width of the waveguide (10) is approximately one-half wavelength as determined by the frequency of operation of the backward wave oscillator.

Abstract: A termination device for absorbing RF energy waves in the termination chamber of a traveling wave tube. The termination device is formed by modifying two wedge shaped termination devices of the prior art. Specifically, two well known single wedge termination devices are sliced in half to produce two wedges each one half the thickness of the prior art single wedge device. The two halves are positioned with their newly formed surface, formed by the slicing, in opposed facing contact. The new double wedge thus has the same thickness as the prior single wedge and is readily accommodated within the termination chamber. The double wedge termination device greatly reduces small signal gain variations across the operating frequency band of the traveling wave tube.

Abstract: This oscillator comprises a periodic structure line constituted by a succession of vanes having an orifice in which propagates a linear electron beam. This line is placed over a cavity constituted by a straight parallelepiped which has a rectangular base, whose dimensions are determined in such a way that it behaves like a waveguide at the cut-off frequency, along the longitudinal axis of the line and on a transverse magnetic or TM.sub.mn mode with m=1, 3, 5 etc. and n=1, 2, 3, 4 etc. Coupling slots are provided on the cavity between two successive vanes and in a gap between pairs of vanes. The anode voltage of the beam and the distance between two successive vanes are selected in such a way that the cavity resonates at the cut-off frequency and on the .pi. mode. Applications include measuring oscillators and heterodyne radar transmitters and receivers.

Abstract: A crossed-field amplifier tube with a cathode slow wave structure at a high electrical potential is coupled to a high frequency of source and a load by a direct current isolated radio frequency transition. The transition is contained within the vacuum of the tube to prevent electrical breakdown between the transition and ground.

Abstract: In the last section of a delay line having coupled cavities for a traveling-wave tube, the following parameters are progressively increased in the direction of propagation of the electron beam: the diameter of the opening provided for the passage of the electron beam, thus making it possible to ensure better transmission of the beam and consequently to ensure higher efficiency as well as lower heat build-up; the ratio (D.sub.2 -D.sub.1)/2 of the cavity nozzles; and the thickness of the walls which are common to two adjacent cavities.

Abstract: The current which passes through the vertical deflector of a transistorized color television receiver is produced by a circuit comprising an active switch controlled and modulated at the line frequency and supplied by line retrace pulses delivered by the secondary winding of a line transformer. The voltage at the terminals of an assembly compring a capacitor in series with the vertical deflector has a constant sign which is independent of the current passing through the deflector. The same secondary winding of the line transformer supplies both the vertical scanning circuit and a rectifier circuit for producing a d.c. voltage, in particular for the supply of video amplifiers.

Abstract: An improved slow wave circuit especially useful in backward wave oscillators includes a slow wave circuit (10) in a waveguide (12) as shown in FIG. 1. The slow wave circuit is comprised of rings 11 disposed between and attached to respective stubs (13,14). The stubs (13,14) are attached to opposing sidewalls of the waveguide (12).To the end that opposed, interacting magnetic fields will be established to provide a very high coupling impedance for the slow wave structure, axially orientated bars (20) are connected between rings in alternate spaces and adjacent to the attachment points of stubs 13. Similarly, axial bars (21) are connected between rings in the spaces which do not include bars (20) and at points adjacent to the attachments of bars (21).FIG. 2 shows the current loops (22,23) available because of the inventive structure.FIG. 3 shows that rings 11 may be half rings of 180.degree. arc.FIG. 4 illustrates that the rings or half rings (11) with stubs (13,14) may be formed of flat metal ribbons.

Abstract: The invention relates to a high gain crossed field amplifier tube.Such a tube comprises in a vacuum enclosure 1 a cathode 2 and a delay line 3, itself constituted by an input line 31 whose height is less than that of the output line 32.The invention is applied to radio transmission systems.