US2891191A - Backward wave tube - Google Patents

Backward wave tube Download PDF

Info

Publication number
US2891191A
US2891191A US392946A US39294653A US2891191A US 2891191 A US2891191 A US 2891191A US 392946 A US392946 A US 392946A US 39294653 A US39294653 A US 39294653A US 2891191 A US2891191 A US 2891191A
Authority
US
United States
Prior art keywords
wave
backward
circuit
electron
path
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US392946A
Other languages
English (en)
Inventor
Heffner Hubert
Kompfner Rudolf
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Corp
Original Assignee
Bell Telephone Laboratories Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE533398D priority Critical patent/BE533398A/xx
Priority to NL191722D priority patent/NL191722A/xx
Application filed by Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US392946A priority patent/US2891191A/en
Priority to FR1108860D priority patent/FR1108860A/fr
Priority to DEW15032A priority patent/DE1105999B/de
Priority to GB33150/54A priority patent/GB772002A/en
Priority to CH332990D priority patent/CH332990A/fr
Application granted granted Critical
Publication of US2891191A publication Critical patent/US2891191A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J25/00—Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons
    • H01J25/34—Travelling-wave tubes; Tubes in which a travelling wave is simulated at spaced gaps
    • H01J25/36—Tubes in which an electron stream interacts with a wave travelling along a delay line or equivalent sequence of impedance elements, and without magnet system producing an H-field crossing the E-field
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J25/00—Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons
    • H01J25/34—Travelling-wave tubes; Tubes in which a travelling wave is simulated at spaced gaps
    • H01J25/36—Tubes in which an electron stream interacts with a wave travelling along a delay line or equivalent sequence of impedance elements, and without magnet system producing an H-field crossing the E-field
    • H01J25/40—Tubes in which an electron stream interacts with a wave travelling along a delay line or equivalent sequence of impedance elements, and without magnet system producing an H-field crossing the E-field the backward travelling wave being utilised

Definitions

  • This invention relates to electronic apparatus of the kind "now generally designated as traveling Wave tubes which utilizekthe interaction between atraveling 'electromag'netic wave and an electron stream.
  • the problerir ⁇ is complicated because the impedancelof the mostfel'licientnf hl ⁇ backward lwaive .circuits oscillation band, ⁇ makir ⁇ igit diiicnlt ⁇ to' wellmatch'ed t the circuit ⁇ continuously for good coupling.
  • one object of the present invention is to as is important ICC 2 ⁇ facilitate the enicient abstractionlof oscillatory energy from a backward wave oscillator.l
  • Another object is to increaseI the frequency bandt over which a backwardmwave oscillator may be convenieutly and efficiently operated.
  • Antherobject is to make practical in traveling wave tubes the use of backward wave" circuits which although of high impedanlceland thus well suited ⁇ for propagating a waves for" interaction with an electron beamrcannot readily beA coupled to ⁇ tl'iemoreuusual forms of Wave transmission lines.
  • Another object ⁇ is to makethe output level. of a backward wave oscillator more uniform with frequency overy its operating range.
  • a backward wave oscillator in accordance with the invention is ⁇ modified to include in addii tion to its wide range - ⁇ backward wave circuit a separate broad brand forward wave typeinteraction circuit, for
  • an oscillator in accordance with the invention can be made to have a more nearly constant power output over its operating band than previously a known backwardY wave oscillators by making internally p both ends of the" ⁇ ybackward ⁇ wave circuit substantially s reliectionless, and operating the ⁇ forward wave circuit at a constant voltaget Alternativelyfamplitude modu-.r
  • lation may be -impressedon the Voscillatory wave by A varying in accordance with modulating intelligence either the voltage on current in theelectron. beam. i
  • theroscillatora can be modified to mix a radlo frequency signal with the oscillatory wave by applying such a signal as an input to the upstream end of thejgforward wave circuit ⁇ for interaction with ⁇ the electron beam on which already exists an oscillatoryspacew charge wave.
  • Patented Jumel, 1959 a in accordance with Athe invention will 4be well suited for use ,as a frequency modu- ⁇ the Aforward wave circuit aroundthe value which results in maximum amplification or thel and the amplified output wave is abstracted at the upstream end of the circuit.
  • An important advantage of such an amplifier is that while the frequency band over which amplication may be secured for a given electron beam velocity is small thispass band can be readily shifted over a wide region merely by varying the velocity of the electron beam. Accordingly, such an amplifier is ⁇ well suited for use as an electronically tunable filter.
  • one of the problems in the use of such an amplifier is the strong tendency it has to oscillate in a backward wave mode when high gains are sought, which tendency restricts the gain which can be achieved stably.
  • another object of the present invention is
  • a backward wave amplifier in accordance with the invention includes a separate forward wave circuit along they path of ofw positioned downstream Vrelative to the backward wave interaction region.
  • input waves to be amplified are applied to the downstream end of the backward wave circuit for travel therealong for impressing a relatively low level space charge wave on the electron stream which, in turn, induces a forward traveling Wave in the forward wave circuit which is further amplified and then abstracted at the downstream end of the forward wave circuit.
  • Such an amplifier retains the useful electronically tunable filter properties of thc backward wave amplifiers known hitherto and yet permits high and relatively uniform stable gain in the pass band. Stability is enhanced by utilizing the backward wave interaction circuit to excite a space charge wave on the electron beam which although of sufficient level to induce a forward traveling wave on the forward wave circuit is of insufficient level to initiate and sustain backward wave oscillations.
  • Fig. 1 shows a frequency modulator in accordance with the invention which utilizes a bifilar helix as the backward wave circuit
  • Fig. 2 shows Van amplitude modulator inaccordance with the invention which utilizes a loaded Lecher-line as the backward Wave circuit
  • Figs. 3A through 3D show a radio frequency mixer in accordance with the invention which utilizes a loaded wave guide as the interaction circuit
  • Figs. 4A and 4B show a backward wave amplifier which employs a slotted hollow cylindrical conductor as the backward wave circuit.
  • the various tube elements are enclosed in an evacuated glass envelope 11.
  • an electron source which is the cathode 12A of an electron gun 12 and the collectorv electrode 13 positioned in target rela* tion with the source.
  • the electron flow is focused by suitable means, not shown here, to be coaxial with the axis of the tube envelope.
  • the backward wave circuit comprising a bifilar helix 14 which serves effectively as a helically coiled balanced transmission line.
  • Patent 2,843,792 issued July 15, 1958, of J. R. Pierce.
  • Positioned downstream along the path of flow is the forward .wave circuit comprising the single wire helix 15.
  • the helix 15 is positioned coaxial with the tube envelope and with the path of flow.
  • the bifilar helix 14 on the other hand is positioned vto have itsV axis parallel to but displaced from the tube axis and the axis of the path of fiow. The reasons for this will be discussed hereinafter.
  • both ends of the backward Wave circuit are terminated internally to be substantially reflectionless.
  • dissipative material such as aquadag
  • the thicknesses of the end coatings 16 and 17 being tapered to provide a broad band dssipative termination.
  • the upstream end of the forward wave circuit is terminated in a similar manner by the coating 18 deposited along the inner surface of the envelope along portions adjacent its upstream end turns.
  • the useful energy is abstracted at the downstream end of the helix 15 by suitable coupling means.
  • the downstream end of the helix 15 is connected by way of the impedance matching section 19 to the coupling strip 20.
  • the impedance matching section 19 comprises a section of helix in which the helix pitch increases gradually.
  • the coupling strip 20 is positioned to couple to the electric vector in the rectangular wave guide 2,1 which is closed at one end and leads to the utilization means at its other end.
  • Various other arrangements are known to workers in the art for coupling an external wave transmission line to a single Wire helix.
  • the velocity of the electron beam past the backward wave circuit is adjusted to be in synchronism with the phase velocity of a spatial harmonic component of a wave of the desired frequency setfupby noise components on the beam at the downstream end of the backward wave circuit for travel upstream therealong.
  • the velocity of the electrons should be adjusted to be approximately maintained by lead-in conductors from voltage source 22. In some arrangements, it will be convenient to maintain a D.C.
  • the modulating intelligence is used to vary the velocity of the electron beam past the backward wave circuit, thereby changing I... s? correspondingly the oscillatory frequency.
  • a -source 23 of modulating voltage-under ⁇ control of the', modulating ⁇ intelligence is inserted seriallyin the conductive path between theuelectron ⁇ source and the backward wavecircuit. .M
  • the backward traveling growing oscillatory wave bunches the forward flowing electron beam which may beconsidered as giving rise thereon to a forward traveling space charge wave.
  • This space charge wave subsequently inrits passager ⁇ past the forward wave circuit induces a forward-traveling electromagnetic wave in the forward wave circuit whichutravels therealong.
  • this ⁇ travelingwave ⁇ can be made to interact with ⁇ the electron t. beam whereby it is ⁇ amplified.
  • T he ⁇ amplified wave is ⁇ abstracted for utilization at the downstream end of the forward wave circuit by the output coupling means.
  • the velocity ofthe electron beam past the forward wave circuit is adjusted to be approximately equal to the phase velocity of the forward traveling wave' alongthe helix 15 in accordance with the usual practice in helix-type traveling wave tubes. different from the velocity of the beam past the backward wave circuit.
  • the relative velocitiespast the two circuits are dependent on the relative voltages on the two circuits.
  • For controlling the electron velocity a potential difference is maintained between the electron source and the helix V by suitable lead-in conductors fromxthevoltage source 24.
  • a wave traveling along the parallel conductors will because of Athe presence of the cylinders 46 setup strong spatial harmonic components along with the tube axis which can be made spatial harmonic components may be ⁇ adjusted by the periodicity and length of the cylinders.
  • the velocity fof the electron beam may be adjusted by the accelerating voltage provided between the succession of annular cylinders and the electron source.
  • the frequency of the oscillatory wave is This velocity can .either be equal to or small along the helix axis, for ⁇ good spatial harmonic f interaction it is advantageous to displacethe path of flow ofthe beam from-the helix axis to a regionof ⁇ stronger spatial harmonic components.
  • interaction with ther fundamental mode ofthe traveling wave which is ⁇ strong along the helix axis is usually preferable ⁇ to spatial harmonic interaction, and, accordingly,jitris desirable to havethe path of electron flow past the single wire helix along the helixaxis.
  • the forward wave circuit can be ⁇ operated to have a frequency response which is complementary to the frequency response to the backward wave circuit.
  • the frequency responses of ⁇ thebackwardand forward wave circuits may be ⁇ chosen to provide an output of anydesiredfrequency ⁇ characteristic.
  • Suitable ⁇ means not shown are employed to maintain the electron beam aligned with the ⁇ tube axis.
  • Such means may include either magnetic focusing equipment ortmeans for achieving a spatially alternating time-constant field ⁇ along the path of ⁇ flow.
  • the backward wave circuit utilized to modulate the electron beam and set up space charge oscillatory waves thereon comprises a Lecher system including the two parallel straight conductors 44 and 45 positioned diametrically opposite along the tube axis alternately from ⁇ which ⁇ is conductively ⁇ supported a linear array of annular conductive Ycylinders 4,6 ⁇ which are spaced varied to tune the oscillatory frequency. ⁇
  • the two ends of the backward wave circuit are made substantially retlectionless by the insertion in- ⁇ ternally of dissipative terminations.
  • each end of the backward wave circuit there is inserted a pair of dielectric rods 48, 49, each of which rods is coated with lossy material, the thickness of the coating ⁇ increasing gradually to make reflectionless ⁇ terminations of each pair of rods.
  • the two rods of each pair preferably are disi posed diametrically opposite one another and adjacent to the glass envelope 4l in the regions between conduc- ⁇ tors Maud 45.
  • the forwardwave circuit comprising the single wire helix 5t) is positioned along the path of flow coaxial with the tubefaxis downstream of the forward wave circuit "waves set up on theelectron beam by the backward wave circuit induce a forward traveling electromagnetic wave on the helix.
  • the helix 5@ is made substantially reilectonless at its upstream end by a dissipative coating 5l alongtheinner surfaceof that portion of the tube envelope adjacent to its end turnsas described above.
  • the output wave is abstracted at thefdownstream end of the helix by a suitable coupling means 52 which, for example, is of the kind described above in the tube shown in Fig. ⁇ l.
  • the retardation characteristics ofthe helix are in this case also chosen so that the phase velocity of the fundamental component of a forward traveling wave is approximately equal to the velocity of the therealong beam therepast, which beam velocity is controlled by the voltage diiference'between the electron source and thehelix.
  • it is a well-known characteristic of helix-type traveling wave tubes that there exists an optimum ⁇ beam voltage, dependent on various parameters, ⁇ forwhich there results maximum interaction between the 52 of ⁇ modulating voltage is inserted in series with the ⁇ ⁇ voltage supply 53 to establish by-suitable lead-in conductors the accelerating potentials on the helix 50.
  • amplitude modulation may be achieved by modulating in accordance with signal intelligence the current of the electron beam, ⁇ provided only that precautions are ⁇ taken to insure that the current never falls belowy
  • a suitable potential diier- ⁇ The rods extend l, preferably for a. distance of several operating wavelengths the tube shown in Fig. ⁇ 2, intelligence to vary the the amount needed to sustain oscillations on the backward wave circuit.
  • the various tube elements are enclosed in an evacuated glass envelope 61.
  • an electron source 62 and a target electrode 63V define a path of electron flow coaxial with the longitudinal axis of the tube.
  • the backward wave circuit in this tube comprises a conductive cylindrical wave guide 64 which extends along an upstream portion of the path of flow and which is loaded by a succession of transverse slat members 65 which extend across the wave guide in a di-ametric fashion.
  • the slat members are spaced apart along the path of flow, and each successive member is rotated about the longitudinal axis a predetermined angle with reference to the immediately preceding member.
  • Each of the slat members is apertured and the apertures are aligned in a linear array coaxial with the tube axis for passage of the electron flow therethrough. Moreover, from each slat there is supported a short vconductive cylinder 66 for surrounding the path of flow.
  • a voltage source 73 is connected between the Wave guide 64v and the electron source 62. 'It is found characteristic of such a wave circuit that a Wave propagating in a direction opposite to that of electron iow will set up along the tube axis stron-g spatial harmonic components. In particular, it is characteristic that the fundamental or lowest order spatial harmonic mode of a wave whose group velocity is in a direction opposite to that of electron flow will have a phase velocity in the direction of electron flow.
  • a circuit of this kind is analogous to an artificial line made up of a ladder network of shunt inductances and series capacitances, the successive slat members acting as inductive posts for forming a series of shunt inductances and the spaced array of cylinders serving to introduce the intermediate series capacitances.
  • the phase shift advances in a direction opposite to the direction of wave propagation along the line.
  • the forward wave circuit which again comprises a single wire helix 69 is disposed along the path of flow downstream of the backward wave circuit for utilizing the oscillatory space charge waves set up on the beam in the manner described above.
  • an input wave which is to be mixed with the oscillatory wave is inserted into the forward Wave circuit at its upstream end by coupling means 70, and the mixed signal is available at the downstream end of rthe forward wave circuit for abstraction by output coupling means 71.
  • the tendency to self oscillations may be ourbed by making this helix'substantially nonreciprocal in its attenuation properties by the insertion therealong of a magnetically biased ferrite element, as is described in copending application Ser. No. 362,177, filed June 17, 1953, by R. Kompfner and H. Suhl.
  • the helix is maintained at a suitable positive potential with respect to the electron source by lead-in conductors connected to the voltage supply 74.
  • the retardation characteristics of the helix and the velocity of beam are-adjusted for interaction between the beam and the Iwave.
  • the oscillatory space charge wave on the electron beam sets up avforward traveling wave in the forward wave circuit which is mixed with the input Wave also applied thereto. Then when the levels of the two signals become suiciently high to result in operation in the nonlinear region of the tubes amplifying characteristics, there result the modulation products of the two waves of which a particular one may be favored by operation in a dispersive region of the circuits phase velocity versus frequency characteristic. Additionally, it may be desirable to lter the output to remove the fundamental frequencies and undesired modulation product frequencies.
  • the various elements of the backward wave amplifier are enclosed in the evacuated glass envelope 81.
  • an electron source 82 and a target electrode 83 define a path of ow of an electron beam along the longitudinal axis of the tube.
  • Suitable focusing means not shown are utilized to keep the electron ow straight.
  • the backward wave circuit which in this instance comprises the annular conductive cylinder 84 which has a succession of lateral yslots or cuts 85 spaced apart longitudinally therealong. The slots are cut in an interleaved pattern, adjacent slots being on diametrically opposite sides of the cylindrical surface.
  • the slots are relatively deep, leaving only relatively small conductive strips 86 integral with the conductive surface in the regions of the slots.
  • Such a structure exhibits along its axis strong spatial harmonic components of a wave propagating therethrough.
  • the cylinder 84 is positioned to have its axis parallel to the longitudinal axis of the tube along which ows the electron beam.
  • An input wave guide 88 of rectangular cross section is used to supply input signals to the downstream end of the backward wave circuit.
  • the wave guide 88 has its narrow side walls apertured for passage therethrough of the tube envelope and the wave guide is positioned along the tube envelope so that the vdownstream end of the cylinder is bridged across the apertured ⁇ side walls of the guide.
  • a conductive sleeve 90 extends from the wave guide wall for shielding that portion of the transition region not included within the wave guide.
  • One end of the wave guide is closed and the other end leads olf to a signal lsource.
  • the upstream end of the backward wave circuit is made substantially reectionless by the insertion of a dissipative termination 87 comprising a pair of coated dielectric rods of the kind shown for terminating the backward wave circuit shown in Figs. 2 and 3. In this case the rods are positioned intermediate the glass envelope 81 and the conductive cylinder 84, as shown in Fig. 4B.
  • the forward wave circuit again comprises a helically wound conductor 91 disposed downstream along the path of ow coaxial with the tube axis whereby the electron beam passes axially therethrough.
  • the upstream end of the forward wave circuit is made substantially reectionless by the insertion of a resistive termination in the form of a coating 92 of dissipative material on the portion of the inner surface of the envelope adjacent the upstream end turns of the helix 91. It should not be necessary to insert loss along the intermediate portion of the forward wave circuit for tube stability if the upstream end of the forward wave circuit is made sufficiently reiiectionless.
  • the amplified output wave is abstracted at the downstream end of the forward wave circuit by coupling means 93.
  • the backward wave circuit portion of the tube serves primarily as a narrow pass band filter whose pass band can be varied electronically.
  • the pass band is controlled by the velocity of the electron beam past the backward wave circuit which can be varied by chang- Positioned ing the voltage difference wave is suiciently near to the velocity ofthe electron beam whereby good interaction between the beam, ⁇ and wave results.
  • ⁇ 'Ille velocity ofthe beam is controlled by the voltage supply ⁇ 95 used to ⁇ establish a potential difference between the helix and the electron source.
  • this embodiment still retains the advantages of a conventional backward wave amplifier in that the electron bunching process will be controlled by the velocity of the electron beam, the velocity of the beam having to be such as to permit interaction between the beam and a forward traveling spatial harmonic of the backward traveling signal wave.
  • This makespossible electronic control of the pass band properties of the am plifier.
  • high output powers are desired measures maybe taken to increase the beam current past the forward wave circuit as, for example, by the provision ⁇ of an additional electrn source ⁇ in ⁇ the region intermediate the backward and forward wave circuits.
  • both backward and forward wave interaction circuits may be employed.
  • the path of flow of the electron beam need riotmbcstraight, but may be circular as is characteristic of someforms of traveling wave tubes, particularly those" ⁇ of "the magnetrontype which employ crossed electric and magnetic fields.
  • pulsed operation maybe achieved by the insertion of suitable detlectingmeans interposed between the back- ⁇ ward and forward wave circuits for makingthe flow past the forward wave circuit intermittent without disturbing the oscillatory behavior of the backwardwave circuit.
  • suitable detlectingmeans interposed between the back- ⁇ ward and forward wave circuits for makingthe flow past the forward wave circuit intermittent without disturbing the oscillatory behavior of the backwardwave circuit.
  • each of which is frequency 'modulated but whose phase is continuous from pulse to pulse.
  • abackward wave interaction circuit characterized in that a wave traveling with a group velocity therealong ⁇ in a given direction will give rise to space harmonic components which have a phasevelocity in the opposite direction positionedupstream along the path of electron flow for yimpressing space charge waves on the electron beam,cdssipative termination means locatedsolely within ⁇ said device for making the upstream end of the backward wave circuit ⁇
  • various forms of substantially retlectionless, ai, forward wave interaction circuitl positioned .downstream along the ⁇ path of ow withrespect to said backward wave circuit in which the..
  • harmonic components which have a phase velocity in the opposite direction positioned upstream along the path of flow for ward wave interaction ⁇ circuit positioned ydownstream along the path of ⁇ flow with respect to: said backward ⁇ wave circuit inwhich the oscillatory space charge waves excite forward traveling waves, Vand means to couple oscillatory wave energy from the downstream end of ⁇ the forward wave circuit.
  • a backward wave circuit characterized in that a wave traveling with a group velocity therealong in a given direction will ⁇ give rise to space harmonic components which have a exciting space charge waves on the electron beam, dissipative termination means located solely within saidV modulator for making the upstream end of the backward wave circuit substantially,reilectionless, means controlled by modulating intelligence for varying the ⁇ velocity of the electron beam past the backward wave circuit, a forward wave circuit positioneddownstream along the path of ow with respect to said backward wave circuit direction will give rise to, space harmonic components.
  • dissipative termination means located solely within said modulator for making the upstream end of the backward wave circuit substantially rellectionless, a ⁇ forward wave circuit positioned downstream along the path of flow with respect to said backward wave circuit in which the space charge waves excite forward traveling electromagnetic waves, means under the control of modulating intelligence for varying the velocity of the electron beam past the forward wave circuit, and means for coupling output ⁇ wave energy from the downstream end of the forward wave circuit.
  • a backward wave circuit characterized in that a wave traveling with a group velocity therealong in a given direction will give rise to space harmonic components which have a phase velocity in the opposite direction positioned upstream along the path of ow for impressing space charge waves on the electron beam, ⁇
  • a backward wave circuit characterized in that -a wave traveling with a group velocity therealong in a given direction will give rise to space harmonic components which have a phase velocity in the opposite direction positioned upstream along the path of flow for propagating therealong an electromagnetic wave in a direction opposite -to the path of electron flow and inducing a space charge wave on the electron beam which travels in the direction of electron flow, dissipative termination means located solely within said device for making the two ends of the backward wave circuit substantially reflectionless, a forward wave circuit positioned downstream along the path of flow with respect to said backward wave circuit in which the space charge wave excites a wave traveling in the direction of electron flow, dissipative termination means for making the upstream end of the forward wave circuit reflectionless, and means for coupling wave energy from thedownstream end of the forward wave circuit.
  • a backward wave circuit characterized in that a wave traveling with a group velocity therealong in a given direction will give rise to space harmonic components which have a phase velocity in the opposite direction positioned upstream along the path of flow for establishing a forward traveling space charge wave on the electron beam, dissipative termination means located solely within said modulator for making the two ends of the backward wave circuit substantially reffectionless, means under the control of modulating intelligence for varying the velocity of the electron beam past the backi ward wave circuit for varying the frequency of the space charge wave on the electron beam, a forward wave circuit positioned downstream along the path of flow with respect to said backward wave circuit in which the forward traveling space charge wave excites ⁇ a forward traveling electromagnetic wave, dissipative termination means for making the upstream end of the forward wave circuit substantially reflectionless, and means for coupling wave energy from thel downstream end of the forward wave circuit.
  • a backward wave circuit characterized in that a wave traveling with a group velocity therealong in a given direction'will give rise to space harmonic components which have a phase velocity in the opposite direction for inducing a forward traveling oscillatory space charge wave on the electron beam, dissipative termination means located solely within said modulator for making both ends of the backward wave circuit substantially refiectionless, a forward wave circuit positioned downstream along the path of electron flow with respect to said backward wave circuit in which the forward traveling space charge wave excites a yforward traveling electromagnetic wave, means under the control of modulating intelligence forv varying the velocity of the electron beam past the forwardV wave circuit, dissipative termination means for making the upstream end of the forward wave circuit substantially reflectionless, and means for coupling output wave energy from the downstream end of the forward wave circuit.
  • a backward wave circuit characterized in that a wave traveling with a group velocity therealong in a given direction will give rise to space harmonic components which have a phase velocity in the opposite direction positioned upstream along the path of flow, means for applying an input signal to be amplified to the downstream end ⁇ of the backward wave circuit for propagation therealong in a direction opposite to that of electron Vflow for establishing on'the electron beam a forward traveling space charge wave, dissipative termination means located solely within said amplifier for making the upstream end of said backward wave circuit substantially reectionless, a forward wave circuit positioned downstream along the path of flow with respect to said backward wave circuit in which the forward traveling space charge wave on the electron beam induces a forward traveling electromagnetic wave, and means for abstracting the amplified electromagnetic wave at the downstream end of the forward wave circuit.
  • a backward wave circuit characterized in that a wave traveling with a group velocity therealong in a given direction will give rise to space harmonic components which have a phase velocity in the opposite direction positioned upstream along the path of flow, means coupled to the downstream end of the backward Wave circuit for inducing a wave to be amplified for propagation therealong in a direction opposite to that of electron liow for establishing a forward traveling space charge wave on the electron beam, dissipative means located solely within said device for making the upstream end of the backward wave circuit substantially reflectionless, a forward wave circuit positioned downstream along the path of flow with respect to said backward wave circuit in which the space charge wave on the beam induces a forward traveling electromagnetic wave, dissipative means for making the upstream end of the forward Wave circuit substantially refiectionless, and means coupled to the downstream end of the forward wave circuit for abstracting u,for utilization
  • an electron source and a target electrode for defining therebetween a longitudinal path of iiow for an electron beam, a bifilar helix positioned upstream along the path of flow for propagating therealong an electromagnetic wave traveling in the direction opposite to that of electron flow and inducing a forward traveling space charge wave on the electron beam, a single conductor helix positioned downstream along the path'of flow with respect to said backward wave c ircuit in which the space charge wave on the electron beam induces a forward traveling electromagnetic wave, and means at the downstream end of the single conductor 13 helix for abstracting the forward traveling wave for utilization.
  • an electron source and a target electrode for defining a Alongitudinal path of fiow for an electron beam, a Lecher system positioned upstream along the path of ow for propagating therea'long an electromagnetic wave traveling in a direction opposite to that of electron flow Y and inducing a forward traveling space charge wave on the electron beam, dissipative termination means located solely within said device for making the upstream end of the Lecher system substantially reflectionless, said Lecher system comprising a pair of parallel conductors from 'which extend a linear array of annular conductive cylinders through which flows the electron beam, alternate cylinders extending from the same conductor, adjacent cylinders extending from different conductors, a single conductor helix positioned downstream along the path of flow with respect to said backward wave circuit in fwhich the forward traveling space charge wave induces a forward traveling electromagnetic wave, and means coupled to the downstream end of the single conductor helix for abstracting the forward traveling electromagnetic wave for utilization.
  • an electron discharge device in combination, an electron source and a target electrode for defining therebetween a longitudinal path of flow for an electron beam, an annular conductive cylinder positioned for surrounding an upstream portion of the path of flow for propagating an electromagnetic wave traveling in a direction opposite to that of electron flow and inducing a forward traveling space charge wave on the electron beam, dissipative termination means located solely within said device for making the upstream end of the propagating cylinder substantially refiectionless, a succession of transverse diametric slat members spaced apart longitudinally along the cylinder and apertured for passage of the electron flow, successive members being angularly displaced around the cylindrical axis, a single conductor helix positioned along a downstream portion of the path of electron flow in which the forward traveling space charge wave induces a forward traveling electromagnetic wave, and means coupled to the downstream end of the single conductor helix for abstracting the forward traveling wave for utilization.
  • an electron discharge device in combination, an electron source and a target electrode for defining therebetween a longitudinal path of flow for an electron beam, a conductive annular cylinder positioned around the upstream portion of the path of electron flow for propagating an electromagnetic wave traveling in a direction opposite to that of electron flow and inducing a forward traveling space charge wave on the electron beam, dissipative termination means located solely within said device for making the upstream end of the propagating cylinder substantially reflectionless, said cylinder having ysuccessive transverse slots in its cylindrical surface, successi've slots being on opposite sides of the cylindrical surface for forming an interleaved pattern of slots, a single conductor helix positioned around the downstream por- 14 tion of the path of electron flow in which the forward traveling space charge wave induces a forward traveling electromagnetic wave, and means coupled to the downstream end of the single conductor helix for abstracting the forward traveling wave for utilization.
  • a backward wave interaction circuit positioned upstream along the path of electron flow for impressing space charge waves on the electron beam, the backward wave circuit being characterized in that a wave traveling with a group velocity therealong in a given direction will give rise to space harmonic components ⁇ which have a phase velocity in the opposite direction and being adapted to provide an interaction between the electron beam and the space harmonic components to cause growth of said traveling wave, dissipative termination means located solely within said device for making the upstream end of the backward wave circuit substantially refiectionless, a forward wave interaction circuit positioned downstream along the path of flow with respect to said backward wave circuit in which the space charge waves on the electron beam induce forward traveling electromagnetic waves, and means to couple output rwave energy from the downstream end of the forward wave circuit.
  • a backward wave interaction circuit positioned upstream along the path of electron flow and in which there is induced by the electron beam an electromagnetic wave which travels therealong in the direction opposite to that of electron flow and gives rise to space harmonic components which have a phase velocity substantially equal to that of the electron flow with which components the electron beam interacts, whereby the induced wave grows and space charge watves are impressed on the electron beam, dissipative termination means located solely within said device for making the upstream end of the backward wave circuit substantially refiectionless, a forward wave interaction circuit positioned downstream along the path of flow with respect to the backward wave circuit in which the space charge waves on the electron beam induce forward traveling electromagnetic waves, and means to couple output wave energy from the downstream end of the forward wave circuit.

Landscapes

  • Microwave Tubes (AREA)
  • Microwave Amplifiers (AREA)
US392946A 1953-11-18 1953-11-18 Backward wave tube Expired - Lifetime US2891191A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
BE533398D BE533398A (pt) 1953-11-18
NL191722D NL191722A (pt) 1953-11-18
US392946A US2891191A (en) 1953-11-18 1953-11-18 Backward wave tube
FR1108860D FR1108860A (fr) 1953-11-18 1954-07-17 Tube à onde rétrograde
DEW15032A DE1105999B (de) 1953-11-18 1954-10-05 Rueckwaertswellenverstaerkerroehre
GB33150/54A GB772002A (en) 1953-11-18 1954-11-16 Improvements in or relating to travelling wave tubes
CH332990D CH332990A (fr) 1953-11-18 1954-11-18 Dispositif comprenant un tube à onde progressive

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US392946A US2891191A (en) 1953-11-18 1953-11-18 Backward wave tube

Publications (1)

Publication Number Publication Date
US2891191A true US2891191A (en) 1959-06-16

Family

ID=23552658

Family Applications (1)

Application Number Title Priority Date Filing Date
US392946A Expired - Lifetime US2891191A (en) 1953-11-18 1953-11-18 Backward wave tube

Country Status (7)

Country Link
US (1) US2891191A (pt)
BE (1) BE533398A (pt)
CH (1) CH332990A (pt)
DE (1) DE1105999B (pt)
FR (1) FR1108860A (pt)
GB (1) GB772002A (pt)
NL (1) NL191722A (pt)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2964671A (en) * 1958-12-03 1960-12-13 Rca Corp High efficiency traveling wave tubes
US3065373A (en) * 1955-11-29 1962-11-20 Bell Telephone Labor Inc High frequency apparatus of the traveling wave type
US3067359A (en) * 1958-05-05 1962-12-04 Commissariat Energie Atomique Structure for linear ion accelerators
US3069588A (en) * 1958-09-26 1962-12-18 Raytheon Co Traveling wave tubes
US3090886A (en) * 1959-07-03 1963-05-21 Int Standard Electric Corp Electric wave generators
US3104344A (en) * 1960-04-06 1963-09-17 Itt High power traveling wave tube
US3292033A (en) * 1961-04-22 1966-12-13 Nippon Electric Co Ultra-high-frequency backward wave oscillator-klystron type amplifier tube
DE1293915B (de) * 1962-07-04 1969-04-30 Csf Hohlraumresonator fuer Laufzeitroehren oder Teilchenbeschleuniger
US3786301A (en) * 1971-11-09 1974-01-15 English Electric Valve Co Ltd Travelling wave tubes
US3825794A (en) * 1973-03-08 1974-07-23 Varian Associates Microwave tube having an improved output section
US6987360B1 (en) * 2004-03-31 2006-01-17 “Calabazas Creek Research, Inc” Backward wave coupler for sub-millimeter waves in a traveling wave tube
CN111063593A (zh) * 2019-12-23 2020-04-24 南京三乐集团有限公司 一种x波段900w脉冲空间行波管
US11493622B1 (en) 2018-02-08 2022-11-08 Telephonics Corp. Compact radar with X band long-distance weather monitoring and W band high-resolution obstacle imaging for landing in a degraded visual environment

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1260638B (de) * 1957-05-22 1968-02-08 Siemens Ag Verzoegerungsleitung mit Bandpasscharakter, insbesondere fuer Lauffeldroehren, und Verfahren zu ihrer Herstellung sowie Lauffeldroehren mit solchen Verzoegerungsleitungen
DE1240999B (de) * 1957-09-26 1967-05-24 Standard Elektrik Lorenz Ag Lauffeldoszillatorroehre
BE627606A (pt) * 1962-03-22
FR2518802A1 (fr) * 1981-12-22 1983-06-24 Thomson Csf Ligne a retard pour tube a onde progressive
CN110310874A (zh) * 2018-03-20 2019-10-08 海鹰航空通用装备有限责任公司 级联倍频返波振荡器

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2541843A (en) * 1947-07-18 1951-02-13 Philco Corp Electronic tube of the traveling wave type
US2585582A (en) * 1949-07-07 1952-02-12 Bell Telephone Labor Inc Electron gun
US2636948A (en) * 1946-01-11 1953-04-28 Bell Telephone Labor Inc High-frequency amplifier
US2654047A (en) * 1948-01-20 1953-09-29 Int Standard Electric Corp Beam traveling wave amplifier tube
US2657305A (en) * 1947-01-28 1953-10-27 Hartford Nat Bank & Trust Co Traveling wave tube mixing apparatus
US2720610A (en) * 1950-07-27 1955-10-11 Kazan Benjamin Noise reducing travelling-wave tube
US2730647A (en) * 1949-06-22 1956-01-10 Bell Telephone Labor Inc Microwave amplifier
US2802136A (en) * 1947-01-25 1957-08-06 Rca Corp High frequency device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2636948A (en) * 1946-01-11 1953-04-28 Bell Telephone Labor Inc High-frequency amplifier
US2802136A (en) * 1947-01-25 1957-08-06 Rca Corp High frequency device
US2657305A (en) * 1947-01-28 1953-10-27 Hartford Nat Bank & Trust Co Traveling wave tube mixing apparatus
US2541843A (en) * 1947-07-18 1951-02-13 Philco Corp Electronic tube of the traveling wave type
US2654047A (en) * 1948-01-20 1953-09-29 Int Standard Electric Corp Beam traveling wave amplifier tube
US2730647A (en) * 1949-06-22 1956-01-10 Bell Telephone Labor Inc Microwave amplifier
US2585582A (en) * 1949-07-07 1952-02-12 Bell Telephone Labor Inc Electron gun
US2720610A (en) * 1950-07-27 1955-10-11 Kazan Benjamin Noise reducing travelling-wave tube

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3065373A (en) * 1955-11-29 1962-11-20 Bell Telephone Labor Inc High frequency apparatus of the traveling wave type
US3067359A (en) * 1958-05-05 1962-12-04 Commissariat Energie Atomique Structure for linear ion accelerators
US3069588A (en) * 1958-09-26 1962-12-18 Raytheon Co Traveling wave tubes
US2964671A (en) * 1958-12-03 1960-12-13 Rca Corp High efficiency traveling wave tubes
US3090886A (en) * 1959-07-03 1963-05-21 Int Standard Electric Corp Electric wave generators
US3104344A (en) * 1960-04-06 1963-09-17 Itt High power traveling wave tube
US3292033A (en) * 1961-04-22 1966-12-13 Nippon Electric Co Ultra-high-frequency backward wave oscillator-klystron type amplifier tube
DE1293915B (de) * 1962-07-04 1969-04-30 Csf Hohlraumresonator fuer Laufzeitroehren oder Teilchenbeschleuniger
US3786301A (en) * 1971-11-09 1974-01-15 English Electric Valve Co Ltd Travelling wave tubes
US3825794A (en) * 1973-03-08 1974-07-23 Varian Associates Microwave tube having an improved output section
US6987360B1 (en) * 2004-03-31 2006-01-17 “Calabazas Creek Research, Inc” Backward wave coupler for sub-millimeter waves in a traveling wave tube
US11493622B1 (en) 2018-02-08 2022-11-08 Telephonics Corp. Compact radar with X band long-distance weather monitoring and W band high-resolution obstacle imaging for landing in a degraded visual environment
CN111063593A (zh) * 2019-12-23 2020-04-24 南京三乐集团有限公司 一种x波段900w脉冲空间行波管
CN111063593B (zh) * 2019-12-23 2022-10-14 南京三乐集团有限公司 一种x波段900w脉冲空间行波管

Also Published As

Publication number Publication date
FR1108860A (fr) 1956-01-18
DE1105999B (de) 1961-05-04
GB772002A (en) 1957-04-10
CH332990A (fr) 1958-09-30
NL191722A (pt)
BE533398A (pt)

Similar Documents

Publication Publication Date Title
US2891191A (en) Backward wave tube
US2672572A (en) Traveling wave tube
US2541843A (en) Electronic tube of the traveling wave type
US2584597A (en) Traveling wave tube
US2222899A (en) Frequency multiplier
US2806177A (en) Signal delay tube
US2575383A (en) High-frequency amplifying device
US2595698A (en) Electron discharge device and associated circuit
US2684453A (en) Growing wave electron discharge device
US2753481A (en) Travelling wave oscillators
US2760161A (en) Traveling wave frequency modulator
US2603773A (en) Modulated oscillator
US2782339A (en) Electron beam amplifier device
US2603772A (en) Modulation system
US2446531A (en) Electron discharge device
US2974252A (en) Low noise amplifier
US2843791A (en) Traveling wave tube
US2945981A (en) Magnetron-type traveling wave tube
US2860280A (en) Electric discharge device and methods
US2828439A (en) Space charge amplifier
US3576460A (en) Impedance match for periodic microwave circuits and tubes using same
US2740917A (en) Electron stream amplifier tube
US2947905A (en) Low noise velocity modulation apparatus
US2794146A (en) Ultra-high frequency amplifying tube
US3101449A (en) Parametric electron beam devices