US2937316A - High frequency apparatus - Google Patents

High frequency apparatus Download PDF

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Publication number
US2937316A
US2937316A US720865A US72086558A US2937316A US 2937316 A US2937316 A US 2937316A US 720865 A US720865 A US 720865A US 72086558 A US72086558 A US 72086558A US 2937316 A US2937316 A US 2937316A
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US
United States
Prior art keywords
grid
wires
aperture
leakage
cathode
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
US720865A
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English (en)
Inventor
Louis F Moose
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 NL236168D priority Critical patent/NL236168A/xx
Application filed by Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US720865A priority patent/US2937316A/en
Priority to DEW24872A priority patent/DE1112210B/de
Priority to BE575279A priority patent/BE575279A/fr
Priority to GB6103/59A priority patent/GB846665A/en
Application granted granted Critical
Publication of US2937316A publication Critical patent/US2937316A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/54—Amplifiers using transit-time effect in tubes or semiconductor devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J21/00—Vacuum tubes
    • H01J21/02—Tubes with a single discharge path
    • H01J21/06—Tubes with a single discharge path having electrostatic control means only
    • H01J21/065—Devices for short wave tubes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J21/00—Vacuum tubes
    • H01J21/36—Tubes with flat electrodes, e.g. disc electrode

Definitions

  • This invention relates to electron discharge devices and more particularly to such devices having a close spaced cathode and control electrode forming part of an input cavity.
  • Such a tube as best seen in the Gormley et al. patent, has a flat planar cathode and closely spaced therefrom a flat control grid comprising an apertured plate across which extends a plurality of parallel wires.
  • an input cavity is formed which includes the cathode and control grid and is partially defined thereby; the anode is advantageously a part both of an output cavity including the control grid and of a coaxial line output which is coupled, by a suitable coaxial-to-waveguide transducer, to an output wave guide.
  • a suitable coaxial-to-waveguide transducer to an output wave guide.
  • control grid has priorly comprised a circular aperture across which the wires extend. While this would appear to be a physi-' cally symmetrical arrangement, in actuality it has been found that such a grid structure is, in fact, electrically asymmetrical.
  • the asymmetry of the grid structure is caused by the parallel wire structure which introduces leakage gaps of varying length in the axis parallel to and perpendicular to the direction of the grid wires.
  • the input cavity gives rise to an asymmetrical field.
  • the asymmetry of the input cavity is the result of the single coupling iris in the side wall of the cavity and the relatively low Q of the circuit.
  • the performances of apparently identical devices in the same circuit were found to vary. Specifically, I have found that the performance of the tube in typical microwave radio installations is dependent upon the orientation of the grid wires in the circuit input cavity. Particularly, variations of gain with tube orientation occur and become more pronounced at high signal levels.
  • I have modified the control grid of such tubes-so that the length of the leakage path in a direction parallel to the grid wires is reduced while the length of the leakage path In this manner I have balanced the leakage with respect to orientation of the grid wires, as the leakage will be greater in a direction parallel to the direction of thegrid winding than it is in a perpendicular direction.
  • the control electrode comprises a fiat supporting disc having an aperture therein narrower in one direction than in the other and a plurality of fine parallel wires extending across the aperture in this one direction whereby the electromagnetic transmission characteristic of the control grid is independent of its orientation in the input cavity.
  • Fig. *1 is a sectional view of a close spaced triode in which a control electrode in accordance with my invention may be incorporated;
  • Fig. 2 is a sectional view of an amplifier cavity in which the device of Fig. 1 may be mounted;
  • Fig. 3 is a plan view of a control electrode in accord-"- Fig. 5 is a plot of the variation of gain with angular" 3 orientation ofa control grid in accordance with my invention.
  • Figs. 6A, 6B, and 6C are figures illustrating the leakage phenomena involved in these grid structures.
  • Fig. 1 depicts a close spaced triode of the type in which the control grid in accordance with my invention may be incorporated.
  • the tube includes a hat cathode 10' supported by a sleeve 11 in which is positioned the heater 12.
  • the cathode is supported 'by arms 14 extending in slots of a ceramic ring 15 on the upper surface of which. is mounted the flat grid or control electrode 17.
  • Connection is vmade to the control electrode 17 through the grid terminal ring I8 having an external threaded portion 19. Connection may be made to the cathode 10 through the metallic shell 20 itself.
  • the anode 22 is positioned directly opposite the cathode and is. supported and insulated from the grid' terminal ring 18 by'a glass or ceramic portion 23. Similarly, the grid ring 18 is. insulated from the cathode housing 20 by a glass or ceramic portion 24'.
  • the device depicted inFig. l is advantageously mounted in. an. amplifier cavity or support as shownin Fig. 2; as this mounting arrangement is "basically similar to that shown for the modulator of W. W. Mumford Patent 2,530,836, November '21, 1950, it also need only be described. briefly.
  • the important aspects of this structure include the input cavity 26 which is coupled through an. iris '27 to the input wave guide 28.
  • the cathode 1.0. and control grid 17 define the upper and. lower elements of the input cavity, connection being made fromone .sideof the wave gu'ide'ZSI to the cathode through fingers 30 hearing against the shell '20 of the lower portion of. the tube and being made to the control grid I7 through.
  • the threaded portion 19 joined electrically to the other side of the wave guide 28 and also through fingers 31..
  • the anode is connected through its terminal 33 to a coaxial line section 34 and. thence to a. coaxiaI-to-waveguide transducer 3 5 .for launching the output wave i'nto output. wave guide 36.
  • the control electrode comprises. a fiat disc or support member 38 having an aperture 39 therein, which aperture-is elongatedin .one. direction.
  • the control grid wires. 40 extend the control grid wires. 40, the wires extending across the width or short length of the aperture 39.
  • thev wires 40 were of .0003 inch diameter wire. and were initially wound a thousand turns to the inch.
  • plot 42 therein depicted is for a tube. utilizing acontro'l grid as disclosed in the aboveamentioned Gormley et al. patent; as can readily be, seen, there is a marked gain variation with orientation up to a 1.5 dbv reduction .in gain.
  • Fig. two plots 43 and Mare depicted for two different tubes both including; a control grid as depicted in Fig; 3 and inaccordance with my invention.
  • the. maximum reduction ingain. being only of the order of .25 db and being random with respect to orientation.
  • Fig. 6B shows the field parallel to the axis of the grid wires at the plane 46 and displaced by half the distance between wires, i.e., the curve 50 illustnates'the field midway between two adjacent grid wires 40.
  • the curve 50 As the strength of the main field in the input cavity 26 or in the output cavity between the control electrode 17 and the anode 22 varies approximately sinnsoidally with the dis tance from the center, a similar condition exists for the leakage field which we are considering now and which is depicted by the curve 50.
  • Fig. 6C shows the teakage field along the plane 46, the curve 51 being along a line perpendicular to the direction of the wires 40.
  • the leakage field through the grid. wires 40 may be equalized and the sensitivity of the tube to orientation of the control grid in the input cavity removed by the control grid as depicted in Fig. 3 wherein the dimension B of the aperture 39' in the direction of the grid wires 40 is only approximately 70 percent as long as the dimension A of the-aperture 3 9 in the direction perpendicular to the direction of the grid wires.
  • the relationship between leakage or orientation sensitivity and the ratio of the dimension B to dimension A appears to be approximately linearso that as the aperture 39 more closely approximates a circular hole, the sensitivity,.w.hichv is not present in. the plot of Fig.v 5, becomes again. apparent, more closely resemblingthe plot of Fig. 4. If.
  • the dimension B is made even smaller relative to dimension A, then the sensitivity will be over'compensated and. a plot similar to Fig. 4,. but shifted by degrees, will depict. the orientation sensitivity. Further, if the dimension- B. ismade too small, there may beexcessive grid shielding of the cathode, reducing the emissionfrom the cathode. unduly.
  • the. aperture 39 is depictedwith. curved ends and straight sides, this is not essential;..instead, the aperture could be entirely rectangular or entirely oval.
  • cathode, the. desired cathode emission, and the configuration of the main. field inthe input cavity are the control? ling factors as to the optimum shape of the aperture 39' itself.
  • Theleakagefield effects which give-rise: to the orientationsensitivity problem, are not; appreciably afiected by the aperture-shape. in the gridtstructure' is itself inan. area. of relati ely high mainfield. in the cavity, by varying, the lengtlrof the grid wires-I have found that I can affect the amountof-leakage field coupling through the grid, as to the hypothetical plane "46. a
  • charge device having a certaingain, means for stabilizing said gain comprising a control electrode within said device having an aperture therein the width of which is approximately .7 the length, and a plurality of parallel wires extending across the width of said aperture, said gain being substantially independent of the length of said threads.
  • High frequency apparatus comprising a hollow conductive support member, an electron discharge device randomly radially oriented in said support member and having a planar cathode and a planar control electrode close- 1y spaced therefrom, said cathode, control electrode, and said support member defining an input cavity resonator having therein an asymmetrical electric field, said control a electrode comprising a disc having an aperture therein which is narrower in one dimension than in the other, said narrow dimension being approximately .7 the length of said other dimension, and a plurality of fine parallel wires extending across said aperture in said narrow dimension, whereby the operation of said device is independent of its orientation in said support member.
  • a high frequency electron discharge device comprising a flat cathode, a control electrode closely spaced there from and forming therewith a portion of an electromagnetic wave supporting member, and an anode, said control electrode comprising a flat disc having an elongated aperture therein, one dimension'of said aperture being .7 the length of the other dimension.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microwave Tubes (AREA)
US720865A 1958-03-12 1958-03-12 High frequency apparatus Expired - Lifetime US2937316A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NL236168D NL236168A (pl) 1958-03-12
US720865A US2937316A (en) 1958-03-12 1958-03-12 High frequency apparatus
DEW24872A DE1112210B (de) 1958-03-12 1959-01-20 Hoechstfrequenz-Scheibentriode
BE575279A BE575279A (fr) 1958-03-12 1959-01-31 Appareil à haute fréquence.
GB6103/59A GB846665A (en) 1958-03-12 1959-02-23 Improvements in or relating to high frequency electron discharge devices and apparatus incorporating such devices

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US720865A US2937316A (en) 1958-03-12 1958-03-12 High frequency apparatus

Publications (1)

Publication Number Publication Date
US2937316A true US2937316A (en) 1960-05-17

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Family Applications (1)

Application Number Title Priority Date Filing Date
US720865A Expired - Lifetime US2937316A (en) 1958-03-12 1958-03-12 High frequency apparatus

Country Status (5)

Country Link
US (1) US2937316A (pl)
BE (1) BE575279A (pl)
DE (1) DE1112210B (pl)
GB (1) GB846665A (pl)
NL (1) NL236168A (pl)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4080546A (en) * 1974-10-16 1978-03-21 Steigerwald Strahltechnik Gmbh Beam splitter for electron beam machines

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2459859A (en) * 1945-03-23 1949-01-25 Standard Telephones Cables Ltd Grid structure for electron discharge devices
US2601025A (en) * 1950-10-02 1952-06-17 Gen Electric High-frequency electric discharge device
US2803782A (en) * 1950-09-22 1957-08-20 Philips Corp Triode thermionic tube

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2459859A (en) * 1945-03-23 1949-01-25 Standard Telephones Cables Ltd Grid structure for electron discharge devices
US2803782A (en) * 1950-09-22 1957-08-20 Philips Corp Triode thermionic tube
US2601025A (en) * 1950-10-02 1952-06-17 Gen Electric High-frequency electric discharge device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4080546A (en) * 1974-10-16 1978-03-21 Steigerwald Strahltechnik Gmbh Beam splitter for electron beam machines

Also Published As

Publication number Publication date
BE575279A (fr) 1959-05-15
DE1112210B (de) 1961-08-03
NL236168A (pl)
GB846665A (en) 1960-08-31

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