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US2937311A - Electron discharge device - Google Patents

Electron discharge device Download PDF

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Publication number
US2937311A
US2937311A US696158A US69615857A US2937311A US 2937311 A US2937311 A US 2937311A US 696158 A US696158 A US 696158A US 69615857 A US69615857 A US 69615857A US 2937311 A US2937311 A US 2937311A
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US
United States
Prior art keywords
wave
tube
radio frequency
slow wave
helix
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
US696158A
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English (en)
Inventor
Chodorow Marvin
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.)
Varian Medical Systems Inc
Original Assignee
Varian Associates 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 claimed from US385357A external-priority patent/US2836758A/en
Priority to GB27312/54A priority Critical patent/GB787249A/en
Priority to FR1147408D priority patent/FR1147408A/fr
Priority to DEV9760A priority patent/DE1052479B/de
Application filed by Varian Associates Inc filed Critical Varian Associates Inc
Priority to US696158A priority patent/US2937311A/en
Application granted granted Critical
Publication of US2937311A publication Critical patent/US2937311A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J23/00—Details of transit-time tubes of the types covered by group H01J25/00
    • H01J23/16—Circuit elements, having distributed capacitance and inductance, structurally associated with the tube and interacting with the discharge
    • H01J23/24—Slow-wave structures, e.g. delay systems
    • H01J23/26—Helical slow-wave structures; Adjustment therefor
    • H01J23/27—Helix-derived slow-wave structures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J23/00—Details of transit-time tubes of the types covered by group H01J25/00
    • H01J23/16—Circuit elements, having distributed capacitance and inductance, structurally associated with the tube and interacting with the discharge
    • H01J23/24—Slow-wave structures, e.g. delay systems
    • H01J23/26—Helical slow-wave structures; Adjustment therefor

Definitions

  • FIG 1 FIE a mmvroa. IE I I5 a FIEIL l Marvin Chodorow Attorney United States Patent ELECTRON DISCHARGEiDEVICE Marvin Chodorow, Menlo.Park, Calif.,..assignon ,td -Vai'iail tssociates, San Carlos, Califqa corporationof Cahorma Original applicationOctoberlZ, 1953, Serial No.'385, 357,
  • the present invention relatesito electron dischargefdevices, such as traveling wave tubes whereinienergy'isexchanged between an electronbeam 'andthefieldof a traveling radio frequency wave,an'd more particularly to -the structure which carries the radio 'frequency' wave within such devices.
  • the 'radio'frequency wave is propagatedon a helical structure, 'whoseidiameter and pitch are such thatthelongitudinalphase velocity of the wave is substantially equal to the"velocity of the electron beam' which is'directed longitudinally of the helix.
  • the operating voltage aswell as :thegeometry of the helix must be properly chosen. It has been determined that good interactionis obtainable in tice by meeting the condition pracvision of a very small electron beam-diameter which is impractical to achieve.
  • eifect represents the practical operating range'of a traveling Wave tube employing. a single helix asv a slow wave structure.
  • This Fourier component has a phase velocity in-the direction-of the beam -and'substantially equal to its velocity.
  • videa'slowwave'structure for a traveling wavetu-be or similar electronic discharge device which -w-i-llprovide optimumgain characteristicsfor high voltage operation.
  • a further object --isto i provide a slow wave structure whichreduces the power in those field components of the traveling wave which do not interact with theelectron beam.
  • Another object of the -invention- is to provide a;.-slow -wave structure which-substantially reduces theproducition of backward wave oscillations.
  • Still another object of the present invention is to provide a novel slow wave structure whichembodies a series ofspaced, axially-aligned parallel rings, each of..which is joined at-diametrically-opposed-points respectively to the rings on eachside thereof.
  • Fig. 1 is a sectional view, in part diagrammatic of a travelingwave tube embodying the present invention
  • Fig. 2- is a cross-sectional view taken along line 2'Z in Fig 1,
  • Fig. 4 is a section taken along line-4-4 of Fig. 3,
  • Fig. 5 isa fragmentary side view of the slow-wave structure of Fig. 1,
  • the present invention is embodied in a slow wave structure which reduces the undesired Fourier comin effect, by winding two helices of substantially the same diameter in opposite directions and applying the radio frequency wave to the resulting slow wave structure in a manner such that the -varying components are reduced and the useful beam interaction comp-onents of the wave propagated on the two contra-wound helices become additive. Since the -varying components encountered in the use of a single helix are reduced by the described slow wave structure, high voltage operation of a traveling wave tube will be permitted with relatively good gain characteristics and backwardwave oscillations will be substantially eliminated.
  • the two modes on oppositely wound helices which correspond to the ordinarily used mode of a single helix can be of the same or of opposite polarity.
  • the first mode where the condition of opposite polarity exists, produces a field between the two helices of relatively great strength and an axial or longitudinal field of negligible value.
  • voltages are of the same polarity, is, to the contrary, possessed of a small field between the helices, and a large longitudinal component, which is that useful for interaction with the beam.
  • Fig. 1 is shown one embodiment of the invention in a traveling wave tube which includes a cylindrical glass casing closed at one end by a collector 11.
  • the collector 11 is hermetically sealed at its periphery to the glass casing 10 and has a central bore 12 for the collection of electrons which have traversed the length of the traveling wave tube.
  • the collector 11 is maintained at a desired positive potentialwith respect to the cathode 13 of the tube by a suitable direct current voltage source indicated at 14; the cathode 13 beingmounted at the other extremity of the glass casing 10 within a glass cup 15 which is joined thereto in sealed relation by the cylindrical peripheral portion 16a of a focusing ring 16.
  • the juncture is such that the focusing ring 16 is supported so as to direct electrons emitted from the cathode 13 in substantially a small, rectilinear beam axially or
  • the cathode 13 is heated by a suitable filament connected to a filament voltage source shown schematically at 17 to produce the described emission and a positive potential is applied to the focusing ring 16 from a direct current voltage source 19.
  • the electrons are maintained in 'a small beam through the tube by means of a suitable magnetic focus-- ing coil 18.
  • the slowwave structure is supported axially of the tube between the cathode and collector ends thereof by means of three glass rods 21 (Fig. 2) and is provided at each end with an antenna 22 which preferably takes the form of a hollow cylindrical stub.
  • the antenna 22 at the cathode end of the tube receives radio frequency energy from an energy translating device such as a conventional waveguide 23 which is tapered as it approaches the tube to insure proper matching with the slow wave structure and is additionally provided with a short 'lateral flange 24 adjacent the antenna 22 to increase the coupling therebetween.
  • a like structural arrangement provides for coupling radio frequency energyfrom the antenna 22 at the collector end of the tube into an output waveguide section 25.
  • each coaxial line is connected to one end of the slow wave structure at the antenna terminal thereof and the outer conductor can be connected to a metallic shield surrounding the glass casing,
  • the slow wave structure 20 shown in Figs. 1, 2, 3, 4 and 5 embodies the contra-wound helices previously discussed, the structure being fabricated in a particularly simple manner.
  • a series of V-shapedjnotches 26 are cut along one side of a cylindrical metal tube 27 by a milling cutter, indicated in phantom at 28 in Fig. 3, and which passes through thetube as shown by the arrow A in Fig. 4.
  • the tube is then rotated one-half turn and a second series of notches '29 staggered with respect to the first series but of the same configuration are cut from this side of the tube 27.
  • each antenna is connected to the helices at a common antenna terminal indicated at 30.
  • the slow Wave structure of Fig. 1 which, as previously discussed, both reduce the power lost in the non-interacting Fourier components and substantially eliminate backward wave oscillations.
  • a slow'wave structure embodying the contra-wound helix principle comprises by a series of axially-aligned parallel rings 31 each of which is joined to the rings on opposite sides'thereof at points spaced with short longitudinally extending conducting bars 32 whose length is, of course, determined by the velocity of the beam and the frequency of the radio frequency wave.
  • Such a structure is conveniently formed, for example, by means of notches suitably placed along a metal tube, as shown in Fig. 6. Both this and the first described slow wave structure are mechanically rigid-so that they can be mounted in various manners within a tube depending upon space and structural limitations.
  • the only limitation on such a structure is that the thickness of the tubular support33 be not too great so that the diameters of thehelices 34, 35 will not be too variant. Otherwise, a certain amount of power-will be carried by the'qs-varying components and will thus be lost as useful energy.
  • the contrawound helices can, ofcourse, be formed of wires 36, 37.both of which are wound on the exterior of a glass tube 38, as shown in Fig. 9. Since, in every case, the helices are arranged so as to propagate the mode where the voltages are of like polarity, it is irrelevant, as mentioned hereinbefore whether the helices contact as here in Fig. 9 or are insulated from one another as shown in Figs. 7 and 8.
  • each of the various described contra-wound helix structures is supported by a glass cylinder or by glass tubes.
  • Such supports when utilized with a single helix slow wave structure, cause a reduction in the impedance as previously defined.
  • the noted reduction of power carried by the non-interacting Fourier components of the radio frequency wave which results from the contra-wound helix construction, substantially reduces the losses incurred in glass or any other dielectric supporting members. Consequently, from a number of aspects, the contra-wound helix slow wave structure embodying the present invention optimizes the exchange of energy between an electron beam and the field of a traveling radio frequency wave.
  • the slow wave structure as herein radio frequency wave
  • apparatus for propagating the radio frequency wave comprising a series of spaced axiallyaligned parallel rings each of which is joined at diametrically opposite points respectively to the rings on each side thereof, the halves of said rings defined by said points providing two electrically parallel paths for the propagation of the wave energy.
  • an energy translating device for interchanging energy with said propagating apparatus, said slow wave structure having a single conducting bar connected to an end ring thereof and coupled to said translating device such that the currents in the halves of said rings are in phase, equal and in parallel, whereby longitudinal field components of the wave are additive along such structure.
  • apparatus for propagating the radio frequency wave comprising a slow wave structure provided with a series of periodically spaced conductive rings of uniform diameter alternately connected together with longitudinally extending conductors at diametrically opposite points on the rings, and means for setting up an electron beam and for passing the same through said propagating apparatus.
  • An electron discharge device as defined in claim 3 wherein a pair of energy translating devices are provided for interchanging energy with the ends of said propagating apparatus, said slow wave structure having single antenna terminals connected to bothend rings thereof, said antenna terminals respectively coupling the ends of said slow wave structure to a respective one of said translating devices.
  • slow wave structure for propagating the radio frequency wave comprising a series of spaced axially-aligned parallel rings each of which is joined at diametrically opposite points respectively to the rings on each side thereof and an antenna terminal at each end of said structure diametrically opposite the point at which the end ring is joined to the ring adjacent thereto; a pair of energy translating devices for interchanging energy with the ends of said slow wave structure, said antenna terminals respectively coupling the ends of said slow wave structure to a respective one of said translating devices; and means for setting up an electron beam and forpassing the sam through said slow wave structure.

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  • Microwave Tubes (AREA)
  • Waveguide Connection Structure (AREA)
US696158A 1953-10-12 1957-11-13 Electron discharge device Expired - Lifetime US2937311A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
GB27312/54A GB787249A (en) 1953-10-12 1954-09-21 Travelling wave electron discharge device
FR1147408D FR1147408A (fr) 1953-10-12 1954-10-05 Dispositif à décharge d'électrons
DEV9760A DE1052479B (de) 1953-10-12 1955-11-19 Lauffeldroehre
US696158A US2937311A (en) 1953-10-12 1957-11-13 Electron discharge device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US385357A US2836758A (en) 1953-10-12 1953-10-12 Electron discharge device
US696158A US2937311A (en) 1953-10-12 1957-11-13 Electron discharge device

Publications (1)

Publication Number Publication Date
US2937311A true US2937311A (en) 1960-05-17

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US696158A Expired - Lifetime US2937311A (en) 1953-10-12 1957-11-13 Electron discharge device

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US (1) US2937311A (fr)
FR (1) FR1147408A (fr)
GB (1) GB787249A (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3322996A (en) * 1962-12-17 1967-05-30 Varian Associates Electron discharge devices and molybdenum slow wave structures, the molybdenum slow wave structures having grain alignment transverse to the electron path
US3370197A (en) * 1962-08-29 1968-02-20 M O Valve Co Ltd Travelling wave tubes
EP0013212A1 (fr) * 1978-12-27 1980-07-09 Thomson-Csf Procédé de fabrication d'une ligne à retard hyperfréquence
US4465987A (en) * 1982-09-07 1984-08-14 Hughes Aircraft Company Ring-bar slow wave structure and fabrication method
US6320550B1 (en) 1998-04-06 2001-11-20 Vortekx, Inc. Contrawound helical antenna
CN111640636A (zh) * 2020-06-09 2020-09-08 电子科技大学 一种工作在正二次空间谐波的行波管慢波电路

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114360988B (zh) * 2022-01-07 2023-04-18 电子科技大学 一种v形矩形槽交错双栅波导慢波结构行波管

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB668017A (en) * 1949-06-08 1952-03-12 Vickers Electrical Co Ltd Improvements relating to electromagnetic waveguides
US2725499A (en) * 1949-06-21 1955-11-29 Bell Telephone Labor Inc High frequency amplifying device
US2768322A (en) * 1951-06-08 1956-10-23 Bell Telephone Labor Inc Interdigital filter circuit
US2798183A (en) * 1954-11-29 1957-07-02 Hughes Aircraft Co Traveling-wave tube
US2813221A (en) * 1950-10-02 1957-11-12 Rca Corp Electron beam traveling-wave tube
US2822502A (en) * 1955-04-05 1958-02-04 Hughes Aircraft Co Slow-wave structure
US2824257A (en) * 1953-03-03 1958-02-18 Gen Electric Traveling wave tube

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB668017A (en) * 1949-06-08 1952-03-12 Vickers Electrical Co Ltd Improvements relating to electromagnetic waveguides
US2725499A (en) * 1949-06-21 1955-11-29 Bell Telephone Labor Inc High frequency amplifying device
US2813221A (en) * 1950-10-02 1957-11-12 Rca Corp Electron beam traveling-wave tube
US2768322A (en) * 1951-06-08 1956-10-23 Bell Telephone Labor Inc Interdigital filter circuit
US2824257A (en) * 1953-03-03 1958-02-18 Gen Electric Traveling wave tube
US2798183A (en) * 1954-11-29 1957-07-02 Hughes Aircraft Co Traveling-wave tube
US2822502A (en) * 1955-04-05 1958-02-04 Hughes Aircraft Co Slow-wave structure

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3370197A (en) * 1962-08-29 1968-02-20 M O Valve Co Ltd Travelling wave tubes
US3322996A (en) * 1962-12-17 1967-05-30 Varian Associates Electron discharge devices and molybdenum slow wave structures, the molybdenum slow wave structures having grain alignment transverse to the electron path
EP0013212A1 (fr) * 1978-12-27 1980-07-09 Thomson-Csf Procédé de fabrication d'une ligne à retard hyperfréquence
FR2445607A1 (fr) * 1978-12-27 1980-07-25 Thomson Csf Procede de fabrication d'une ligne a retard hyperfrequence, ligne a retard hyperfrequence obtenue par ce procede et tube a onde progressive comportant une telle ligne
US4465987A (en) * 1982-09-07 1984-08-14 Hughes Aircraft Company Ring-bar slow wave structure and fabrication method
US6320550B1 (en) 1998-04-06 2001-11-20 Vortekx, Inc. Contrawound helical antenna
CN111640636A (zh) * 2020-06-09 2020-09-08 电子科技大学 一种工作在正二次空间谐波的行波管慢波电路
CN111640636B (zh) * 2020-06-09 2021-03-30 电子科技大学 一种工作在正二次空间谐波的行波管慢波电路

Also Published As

Publication number Publication date
GB787249A (en) 1957-12-04
FR1147408A (fr) 1957-11-25

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