US2793316A - High frequency electron discharge device and system - Google Patents

High frequency electron discharge device and system Download PDF

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US2793316A
US2793316A US265014A US26501452A US2793316A US 2793316 A US2793316 A US 2793316A US 265014 A US265014 A US 265014A US 26501452 A US26501452 A US 26501452A US 2793316 A US2793316 A US 2793316A
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electron
cathode
input
space
current
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Elmer D Mcarthur
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General Electric Co
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General Electric Co
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Priority to FR1073483D priority patent/FR1073483A/fr
Priority to CH310960D priority patent/CH310960A/de
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J25/00—Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons
    • H01J25/02—Tubes with electron stream modulated in velocity or density in a modulator zone and thereafter giving up energy in an inducing zone, the zones being associated with one or more resonators

Definitions

  • This invention relates generally to the translation of electromagnetic energy and, in particular, to novel methods and devices utilizing both space charge control of current flow and velocity modulation phenomena for the generation and amplification of electromagnetic waves.
  • One of the more successful types of high frequency electromagnetic Wave tubes is a special space-charge vacuum tube, usually referred to as the disk seal tube.
  • This tube is an outgrowth of the Wellknown low frequency, cylindrical electrode vacuum tube and is chiefly identified by its planar electrode structure which enables very small interelectrode spacings.
  • the disk-seal tube depends for its operation, as does the low frequency vacuum tube, upon space charge control of current fiow to deliver an alternating current to an output circuit.
  • Space charge control of current flow is defined as the varying or modulating of electron flow from a cathode .by changing the electric field at the surface of the cathode.
  • the interelectrode spacings of the disk-seal tube are of the order of 0.1 mm. or smaller. Consequently, the disk-seal tube is limited by the mechanical difficulties inherent in maintaining the requisite close manufacturing tolerances.
  • the velocity modulation tube is another type of high frequency electromagnetic wave tube in which the comparatively long transit times encountered in the microwave frequency spectrum are utilized to advantage, rather than being minimized as in the disk-seal tube.
  • One of the more familiar forms of the klystron comprises an electron gun which produces an accelerated beam of electrons having a constant velocity and density. This constant velocity and density beam is directed through the interaction gap of an input resonator where a high frequency excitation voltage gives each electron an additional acceleration-positive or negative-depending upon the phase and magnitude of the gap voltage during passage of the respective electrons.
  • the beam which now contains electrons of various "ice velocities, is directed through a drift space or region essentially free from external electric fields in which the variations in velocity create density modulation or electron grouping.
  • the electron groups or bunches are then caused to traverse the interaction gap of an output resonator to excite it into oscillation and deliver power to a load. Since the velocity modulation is applied only after direct current acceleration of the electron beam to 'a relatively high average velocity, the requirements for electrode spacings in the input gap are much less severe than in the disk-seal tube.
  • the ideal efliciency of a two-resonator klystron is 58% and is much lower in practice where circuit and beam loading losses are present.
  • the bunched electron stream is caused to excite anoutput circuit whereby power may be delivered to a load.
  • a variety of input electrode-structures may be. employed to obtain the initial space charge control and velocity modulation of the invention. In each case, however, enhanced efi'iciency is obtained by arranging the input electrode structure, in conjunction with operating conditions, to secure a predetermined phase angle between the initial current modulation component provided by space charge control and the total transit time or transit angle of the electrons from the inception of the space charge control to the end of the drift space.
  • the greatest enhancement of efficiency occurs when the time-varying total transit angle leads the space charge control current component in phase by or when the phase angle equals +1r/2, and this is true regardless of the form of input electrode structure and regardless of whether the fundamental or a given harmonic of the input frequency is utilized.
  • a bunching factor-which is a measureof the degree ofbunching of the electron stream as it leaves the drift space is a measureof the degree ofbunching of the electron stream as it leaves the drift space.
  • a bunching factor which is a measureof the degree ofbunching of the electron stream as it leaves the drift space.
  • maximum efficiency for'fundamental frequency occurs when the bunching factor equals 1.47 and the above-mentioned phase angle equals +1r/2.
  • the invention makes it possible to secure very high efiiciencies at harmonic frequencies, thereby enabling the progress of the electronics industry toward the use of higher and higher frequencies.
  • Fig. l is a simplified schematic useful in explaining the invention
  • Figs. 2, 3, 3A, 4, 5 and 6 are graphs which are employed to illustrate the interdependence of various parameters of the invention
  • Fig. 7 is another simplified schematic useful in explaining a diode input structure according to the invention
  • Fig. 7A is a graph illustrating the efiiciency of a diode input structure of the invention
  • Fig. 8 is a simplified section view of a diode input device according to the invention
  • Fig. l is a simplified schematic useful in explaining the invention
  • Figs. 2, 3, 3A, 4, 5 and 6 are graphs which are employed to illustrate the interdependence of various parameters of the invention
  • Fig. 7 is another simplified schematic useful in explaining a diode input structure according to the invention
  • Fig. 7A is a graph illustrating the efiiciency of a diode input structure of the invention
  • Fig. 8 is a simplified section view of a diode input device according to
  • FIG. 9 is a schematic illustration, partly in section, of feedback means which may be employed in conjunction with the devices of the invention.
  • Fig. 10 is a simplified perspective view of another embodiment of a diode input device utilizing wave guides according to the invention.
  • Fig. 11 is a sectionalized representation of another embodiment of the invention especially adapted for high power applications;
  • Fig. 12 is a section view of a further embodiment of the invention in which a triode input structure is utilized.
  • the disk-seal tube and the klystron or velocity modulation tube obtain their operational characteristics from contrasting physical phenomena, i. e., space charge control and velocity modulation of an electron stream.
  • the analytical treatments of these two general microwave tube types have been mutually exclusive and basically divergent.
  • novel methods and devices wherein an electron stream is initially modulated at the same input frequency with both space charge control and velocity modulation and then directed through a drift space; consequently, the heretofore known analytical treatments are not applicable.
  • the following description of the present invention therefore, contains an analysis treating the requisite space charge control and velocity modulation components of an electron stream.
  • this analysis presents a theory which enables a clear and complete description of the invention and also defines the manner in which the various parameters must be arranged to secure the many advantages of the invention.
  • the instantaneous output current caused by the bunched electron stream at the time of its emergence from drift space 1, will be designated i and defined by the following Fourier series:
  • A is the direct current component of output current
  • t is the time of arrival of an electron at the exit end of drift space 1
  • a B A B,, An and En are coeflicients of the alternating components of the output current.
  • die. is the time required for the electrons carrying the charge to move through the distance dx at velocity Ila.
  • lug. is the instantaneous velocity of the electrons while passing through plane 3611.
  • the instantaneous value of current of the electron stream will be designated i at time t when the electrons cross an arbitrarily positioned plane x
  • the symbol x merely identifies the arbitrarily positioned plane and may or may not represent the distance from-the plane .vc to plane 2a, which is located-at the entrance of drift space 1.
  • the current i will be assumed to have alternating and direct current components of arbitrary magnitude and to be defined by the following expression:
  • i r,+1r sin m 7 12
  • l reference axis for the sine wave representing the A. C. component
  • I magnitude of alternating current component measured from Ir
  • t tirne at which electron giving rise to i cross the plane x with the added provisions that i is never negative and that whenever a negative value for i is indicated by'Expression 12., i shall be assumed to be zero.
  • Expression '12 will be readily recognized as the form of the equati'onfor the fundamental component of current flow in a diode, t'riodeo'r tetrode, which arises from the impressed direct and sinusoidal voltag-es.
  • A-s'iscustomary in the treatment of triode'syseveralspecificwave forms which are of particular interest may be derivedfi
  • These are the well-known Classes A, B and C conditions of operation.
  • the fundamental current wave form consists of a direct current component and a superimposed alternating current component of such amplitude that I is equal to or less than I1- and linearly related thereto, whereby Expression 12 may be written:
  • the parameter M is, as may be seen, the ratio of the fundamental of the space charge control component iof electron current to the average current and will be referred to hereinafter as the modulation index of input current.
  • the current is positive during an angle of less than 180 and is zero during the remainder of each cycle.
  • u u ,[1+p sin (wt +a (17), where tr l-average velocity.
  • Equation 25 is the transit angle from x to x, in the absence of an alternating velocity component, and m and m are coefficients of the trigonometric functions. This is an approximation which represents the true equation with an error generally not more than a few percent. Examples will appear hereinafter. Substituting Equation 25 into 24 and expanding the trigonometric term, we obtain:
  • Equation 25b wt +wT +m sin wt +m cos v wt +wT P wT sin wt COS a' p wT' cos wt sm a
  • the size of the functions #1,, 1p, and 1, depend, in a practical adaptation, upon electrode dimensions andoperating conditions and can be determined analytically for any chosen system of electrodes.
  • Equations 32 and 33 may be written respectively as:
  • Equation 39 represents the square of the magnitude of the nth harmonic of alternating current output from drift space 1 when an electron stream, which has been modulated with both space charge control and velocity modulation components as specified hereinbefore, is fed into the drift space. From Equation 39 we may obtain the optimum values for the several variables involved; thus we can determine the specific parameters for input electrode structures and circuits and for drift space 1, such being contemplated by the present invention and more fully disclosed hereinafter.
  • Equation 39 provides a basis for an expression of efficiency. If we define efliciency, 1 in the usual sense as the ratio of input power to output power, we may state that n is the product of Cit/21 and the ratio of peak A. C. output voltage to beam voltage. Thus, to find the value of a for maximum efiiciency we compute the conditionfor which d 0, 2112 To i- From (39) and (40) we have,
  • Equation 45a may be expressed as l 0+!
  • the two sinusoids are displaced by 90, the value of the angle a for maximum efficiency.
  • the total transit angle wT must lead the space charge control component of electron current by 90.
  • Fig. 5 the wave shape of the output current secured according to the invention is represented.
  • curve 8 for M :0 is included.
  • space charge control in addition to velocity modulation is utilized as specified by the invention.
  • Fig. 6 represents the variation of maximum efiiciency, with respect to harmonic ratio, n. As will be observed, the maximum efficiency remains over 50% even for the 15th harmonic of the input frequency. While the foregoing discussion has dealt chiefly with the Class A condition of the space chargecontrol component, the efliciency at the tenth harmonic for Class B operation, which is within-contemplation of the invention, has been calculated to be 97%. With Class C operation, also envisaged, efficiencies are still higher. Therefore, the present invention has especial importance when harmonic frequencies are utilized.
  • a drift space 10 is represented as having a diode input.
  • plane 11 may be considered a cathode and plane 12 an electrode, which may be in the form of a grid, between which is defined an input interaction gap 13 having a width S.
  • plane 12 Following plane 12 is field-free drift space 10 having a length L and being terminated by a plane 14.
  • Plane 15 may be considered as an anode whereby planes 14 and 15 together define an output interaction gap 16. The output current which flows in gap 16 will be computed for this electrode system by following the same pattern and pro-.
  • Vi amplitude of alternating potential difference between 11 and 12.
  • the electron conduction current flow through the arbitrary AX plane and from cathode plane 11 must be the same current which would flow if the frequency were very low.
  • the instantaneous conduction current leaving cathode plane 11 may be computed by Equation 50 even in the microwave spectrum.
  • Equation 53 For present purposes including the determination of the fundamental component of output current which is obtained according to the invention with a device embodying principles illustrated by Fig. 7, only the first two terms of Equation 53 need be considered; neglect of the second order term can be shown to produce an effect of only 2 or 3%. These two terms give the instantaneous current 1",, leaving the cathode at time t'.,:
  • the current i may be calculated from the dimensions of the electrodes and the applied voltages.
  • wt' in terms of wt, for the particular electrode system of Fig. 7. This may be done in the ensuing manner.
  • t It t is defined as the time of arrival of the electron at plane 12, the velocity with '33 which an electron arrives at plane 12 is found from Equation 61 to be eyesore it ponents higher than one, the final solution for all" may be obtained:
  • Equations 63 land 64 may be simplified by defining the The IleXt Illicessary p in ⁇ lemming '2 in terms of t it ti across gap 13 f an l t hi h l ft plane known functions is the calculation of the electron transit 11 at time t' as angle through drift space 10. This region has essentially no electric field except that due to space charge. Neglect- 1 1 0 ing this, the electrons travel through the drift space with Substituting Relation 65 into Equations 63 and 64 protheir entrance velocity expressed by Equation67. The prises transit time T1. through the drift space is, therefore,
  • Equation 69 is a transcendental equation which cannot which is obtained by making a similar approximation to be solved directly for the instantaneous tnans
  • T may Equations 68 and 73 to produce be substituted for T (in this term alone) and Equation 69 becomes 'w T' K L wT'g 2S 0 T 2KT os t 2 sin I g g j ,3 whereby the instantaneous translt angle in-the drift space wT 1 becomes 65 Since we now have the instantaneous transit angle of elec- In view of the fact that the actual angle wt' at the time of arrival of an electron at plane 14 is desired for the remaining calculations, rather than the total transit angle
  • Equation 78 The actual angle wt, at the time of arrival of an electron at plane 14 is Equation 78 may be evaluated by substituting therein the values of QT, and wT'L from Equations 71 and 76 respectively. When this is done and the terms properly arranged, the final solution is:
  • Equation 79 substitution of the values of 1 ⁇ [1 and h from Equations 25d, 25a, and 25 respectively into Equation 25b yields a relation of the same form as Equation 79.
  • Equations 11, 54 and 79 to evaluate the integrals which define the Fourier coefficients, viz. Equations 56 and 57, yields precisely the same final relations as those determined in the foregoing general solution.
  • the output current in gap 16 is given by Equation 39 with values of p and a, termed p and a when referred specifically to the diode input case presently being discussed, determined from along with Equations 81 and 82.
  • the results obtained in the general solution may be specifically applied to the diode input case once the functions ip' 11', and t, have been derived, thereby obviating the necessity of further analysis.
  • Equation 94 it may be seen from Equation 94 that, with one given structure, optimum bunching may be obtained over a wide range of harmonic frequencies by merely altering only the magnitude of K or, practically speaking, the magnitude of the input alternating voltage.
  • the present invention enables operation over a wide range of harmonic ratios with favorable efiiciencies.
  • any of the harmonic ratios may be reached with the same structure operating at the same beam voltage by simply tuning the output resonator (in a manner more fully explained hereinafter) to the desired harmonic frequency and slightly lowering the magnitude of the input alternating voltage.
  • a diode input device comprising an input resonator 20, a drift space .21, which may be defined by a conductive non-magnetic cylinder, and an output resonator .22.
  • Input resonator 20 includes an outerconductor .23 :and an inner conductor 24 between which is inserted a slidable tuning plunger 25.
  • Tuning plunger '25 the position of which determines the resonant frequency of resonator 20, may comprise a plurality of circumferentiallyspaced metallic spring fingers 26 attached to rings 27 and '28 which are separated by insulating material 29.
  • Electromagnetic energy may be supplied to-resonator 20 from a suitable. source (not shown) by means :of a coaxial line 31,.illustratedas capacitively coupled.
  • .A stream or beam of .electons may vbesupplied :tothe diode input device of the invention by an indirectly heated cathode 32 which includes a cup-shapedmember 33 having a thermionically emissive coating 34.upon the inner face thereof and a suitably supported-filament35 therewithin.
  • .Heater current is supplied to filament 35 from a conventionallyrepresented source of direct current 36.
  • Drift space 21 which is essentiallyifree of electric field, comprises a conductive .hollow cylindrical portion .37 which isattached at one. extremity .toouter conductor, 23
  • Orifices 38 and 39 are provided in the input and output ends of portion 37, respectively, to permit the passage through drift space 21 of the electron stream emanating from cathode 32.
  • electrodes illustrated as grids 40 and 41 formed of wires 42 suitably fastened to the end sections of portion 37 beyond the terminations (not shown) of the orifices.
  • Output resonator 22 comprises an outer conductor 46 and an inner conductor 47 between which is inserted a slidable tuning plunger 48.
  • Tuning plunger 48 may be constructed in a manner similar to plunger 25 and may include metallic spring fingers 49, rings 50 and 51, and control rods 52.
  • Inner conductor 47 of output resonator 22 terminates short of the output end section of portion 37 to provide an output gap 53 whereby the bunched electron stream emanating from drift space 21 may excite output resonator 22 into oscillation.
  • Supported from a flanged circular ring 54 attached to inner conductor 47 is an anode member 55 upon which the electrons impinge after exciting output gap 53.
  • Gap 53 is bridged by a cylindrical sealing member 56 of glass or ceramic to permit internal evacuation of the device as hereinbefore mentioned.
  • Power may be extracted from output resonator 22 and supplied to a desired utilization circuit (not shown) by means of a concentric line 57, which is illustrated as capacitively coupled.
  • a conventionally represented source of direct voltage 58 having a potentiometer 59 connected thereacross.
  • Cathode 32 is maintained ,at an adjustably negative potential with respect to grid 40 by means of tap 60, and anode 55 is maintained at an adjustab'ly positive potential with respect to ,grid 41 by means of a tap 61 which may be connected to anode 55 as shown at 62.
  • the length of the input gap 44 between cathode 32 and grid 40, hereinbefore identifiedas S in the diode analysis, may be calculated from Equation 96 for a selected input frequency and beam voltage V0 which is here the voltage between the ground potential of grid 40 and the negative potential of cathode 32.
  • V0 the voltage between the ground potential of grid 40 and the negative potential of cathode 32.
  • the length-of output gap 53 and the magnitude of the;anode voltage may be selected from a rangeof values in a manner now apparent to those skilled in the art to give ,a desired efficient coupling between the bunched electron stream and output resonator 22. If it is desired to operate the device of Fig. 8 as an amplifier at fundamentalfrequency,-we
  • the devices herein disclosed may be operated as generators of electromagnetic waves as well as amplifiers.
  • the manner in which this may be accomplished is illustrated in Fig. 9 wherein numerals employed hereinbefore are used to identify like elements.
  • a section 63 of adjustable length is shown connected to input coaxial line 31 at one end and capacitively coupled to output coaxial line 57 at the other end.
  • Insulators 64 and 65 may be utilized to support the inner conductor 66 Within the outer conductor 67 of adjustable section 63.
  • section 63 may be arranged at the proper length to supply a desired amount of positive feedback from the output to the input of the device whereby electromagnetic oscillations are generated.
  • FIG. 10 there is shown a modification of the invention particularly adaptable for operation at very high frequencies.
  • the illustrated device comprises an input wave guide 68, a drift space 69 and an output wave guide 70.
  • Input wave guide 68 includes a rectangular conductor 71 which is closed at its upper end and hermetically sealed at a convenient position along its length by means of a dielectric member 72.
  • a tuning plunger 73 having an operating rod 74 extending through a hermetically sealed flexible bellows 75 is located in the upper end of wave guide 68.
  • a plurality of flexible spring fingers 76 provide sliding contact between tuning plunger 73 and conductor 71 of wave guide 68.
  • a stream of electrons may be supplied to the device of Fig. by an indirectly heated cathode 77 which includes a flanged, cup-shaped member 78 having a thermionically emissive coating 79 upon the inner face thereof and a suitably supported filament 80 therewithin.
  • Cathode 77 is insulated from conductor 71 for direct current and bypassed thereto for high frequency current by means of dielectric spacer members 81.
  • Heating current is supplied to filament 80 from a conventionally represented source of direct current 82 connected to conductive rods 83 which are hermetically sealed to wave guide 68 by means of a dielectric spacer 84 and a box like member 85.
  • Drift space 69 comprises a generally rectangular portion 86 having an open end 37 which extends into input wave guide 68 and another open end 88 which extends into output wave guide 70. Across open ends 87 and 88, respectively, are positioned electrodes illustrated as grids 89 and 90 which are formed of wires 91 suitably fastened to the sides of rectangular portion 86.
  • a solenoidal winding 92 supplied by a source of direct current may be positioned as indicated about drift space 69 to generate a longitudinal magnetic field for focusing the electron stream which emanates from cathode 77.
  • -Output wave guide 70 is similar to input wave guide 68 and comprises a conductive rectangular member 93 having a tuning plunger 94 hermetically sealed into the upper end thereof. At a convenient position along its length, output wave guide 70 may be sealed from the atmosphere by a dielectric spacer element 95.
  • An anode 96 is positioned with its inner end" adjacent grid 90 as shown and is supported in hermetically sealed relationship within the device by means of a rectangular dielectric section 97 and a flanged plate member 98.
  • Anode 96 is insulated from wave guide 70 for direct current and 20 by-passed thereto for high frequency current by means of dielectric spacer members 99.
  • FIG. 11 there is illustrated another modification of the invention which is particularly adaptable to operation at high power levels.
  • This modification comprises an input resonator 101, a drift space 102, and output resonators 103 and 104.
  • Input resonator 101 is defined by an outer casing 105, an inner cylindrical member 106, a cathode 107 and a cylindrical member 108 having an inverted, somewhat T-shaped, cross section.
  • Input power may be supplied to resonator 101 by means of a capacitively-coupled, hermetically sealed, concentric line 109.
  • Cathode 107 comprises a pair of opposed generally circular plates 110 and 111 having a plurality of circumferentially-spaced, thermionically emissive strips 112 attached therebetween.
  • Heater power may be supplied to cathode 107 from a conventionally represented source of direct current 113 through a rigid conductor 114 secured to plate 111.
  • an electrode illustrated as a grid 115 formed of a plurality of circumferentially spaced wires 116, is positioned.
  • wires 116 are attached to conductive cylinders 117 and 118, the former of which is ca pacitively by-passed to a boss 119 of casing 105 by a dielectric cylinder 120.
  • Conductive cylinder 113 is capacitively by-passed to a boss 121 of casing 105 by a dielectric cylinder 122 and is also capacitively by-passe'd to cylindrical member 108 by a dielectric cylinder 123.
  • Drift space 102 extends radially from the inner ends of bosses 119 and 121 to output gaps 124 and 125 in output resonators 103 and 104, respectively.
  • Power may be extracted from output resonators 103 and 104, which are coupled together through their electromagnetic fields, by means of a magnetically coupled, hermetically sealed coaxial line 126.
  • a suitable coolant may be circulated through a cylindrical space 127 in casing 105.
  • the device of Fig. 11 has similar char acteristics to the devices of Figs. 8 and 10 with the exception that electrode 115 provides a triode input to drift space 102 for a purpose which will be more fully explained later in connection with the device of Fig. l2. Electrons emanating from cathode 107 are affected by the electromagnetic field within input resonator 101 and are given both space charge control and velocity modulation components in the gap between cathode 107 and grid 115. After the bunched electrons cross gaps 124 and 125 to excite output resonators 103 and 104, they are discharged upon an anode portion 128 of casing 105. Operating potentials may be supplied to the device of Fig.
  • Cathode 107 is maintained at an adjustably negative potential with respect to anode 28 by means of a conductor 129', while grid 115 is held at an adjustably negative potential with respect to cathode 107 by means of a conductor 130 which is hermetically introduced into the device as illustrated.
  • a triod'e input to drift space 21 for the purposeof obtaining maximum efficiency over a wide range of values for thebeam voltage.
  • the device of Fig. 12 comprises an electrode shown in the form of a grid 135 inserted between cathode 32 and electrode 40.
  • Grid 135 is formedof transversely extending Wires 136 attached to a flanged conductive washer 137 which extends through dielectric cylinder 45. Washer 137 is conductively connected to a washer 138 through spring fingers 139, and washer 138 is by-passed to input resonator 20 and drift space 21 by means of dielectric washers 140 and 141, respectively. It will now be observed that by maintaining grid 135 at an adjustably negative potential with respect to cathode 32 by means of a tap 142, various values of beam voltage may be selected in conjunction with the voltage of grid 135 to achieve maximum efliciency in accordance with the foregoing principles of the invention.
  • the feedback means illustrated in Fig. 9 or means equivalent thereto may be employed with all the various embodiments of the invention to obtain a high frequency oscillator.
  • the output waves transducing means in the various embodiments of the invention i. e., the resonators and wave guides, may be tuned to a harmonic of the frequency to which the input wave transducing means is tuned. to obtain a high efficiency harmonic amplifier.
  • low frequency modulation voltages may be applied respectively to electrodes 115 and 135 in well known ways to insert intelligence signals into the devices.
  • the present invention provides methods and devices in which the translation of electromagnetic energy is accomplished in novel manner with very high efficiency.
  • the application of both space charge control and velocity modulation components to an electron stream according to the invention may be accomplished with a variety of input electrode structures. Selection of a desired input electrode structure enables determination of the various parameters by means of the equations developed herein. As an example, detailed calculations for a diode input structure have been included in the above description.
  • new and improved methods of and devices for the generation and amplification of electromagnetic waves are realized.
  • An electron discharge device system of the type employing an electron beam comprising a cathode for generating a beam of electrons, means providing a drift space spaced along said beam from said cathode to provide an input gap, electromagnetic wave transducing means coupled to said electron beam in said input gap to supply high frequency fields for modulating said electron beam with a space charge control component, electromagnetic wave transducing means coupled to said electron beam in said input gap to supply high frequency fields for modulating said electron. beam with av velocity modulation cont ponent, the total transit angle of. electrons fromsaid cathode to the exit end of said drift spacehaving a phase angle of about +1r/2 with respect to saidspace charge component, an anode spaced from said exit end. of said drift space, and, output electromagnetic wave transducing means coupled with said electron beam in the space between the exit endof said drift space and said anodefor deriving electromagnetic energy'from said electron beam.
  • An electron discharge device system of the type employing an electron beam comprising a cathode for generating a beam of electrons, means-providing a drift space spaced along said beam from said cathode to provide an input gap, electromagnetic wave transducing-means coupled to said electron beam in said input gap to supply high frequency fields for modulating said electron.
  • beam with a space charge control component electromagnetic wave transducing means coupled to'said electron beam in said input gap to supply high frequency fields for modulating said electron beam with a;velocity-modulation'com ponent, the total transit angle. of electrons from said;
  • said electron beam emerging from said drift space representing an alternating current having a magnitude Cn determined by the relation where in is the direct current'represented by the electron.
  • n is any; integer, p is a bunching parameter dependent upon the magnitude of the velocity modulation component andthe length of said drift space, and M is a modulationindex of the space charge control component, an anode spaced from said exit end of said drift space, and output electromagnetic wave transducing means coupled with said-electron beam in the spacebetween the exit end-ofsaiddrift space and said anode for deriving electromagnetic energy from said electron beam.
  • a system as in claim 7 in which p is approximately quency fields supplied by said first recited cavity resonator.
  • An electron discharge device system of the type employing an electron beam comprising a cathode for generating a beam of electrons, means providing a drift space spaced along said beam from said cathode to provide an input gap, said means including a hollow conductive member maintained at a positive potential with respect to said cathode for accelerating said electron beam in said input gap, a wave guide connected for high frequency currents between said cathode and said hollow conductive member to supply high frequency fields for modulating said electron beam with both space charge control and velocity modulation components, said input gap having an electrical length of 21r at the operating frequency for the positive potential applied to said hollow conductive member an anode spaced from the end of said drift space remote from said cathode, and a wave guide coupled with said electron beam in the space between said end of said drift space and said anode for deriving electromagnetic energy from said electron beam.
  • An electron discharge device system of the type employingan electron beam comprising a cathode for generating a beam of electrons, means providing a drift space spaced along said beam from said cathode to provide an input gap, said means including a hollow conductive member maintained at a positive potential with respect to said cathode for accelerating said electron beam in said input gap, a wave guide connected for high frequency currents between said cathode and said hollow conductive member to supply high frequency fields for modulating said electron beam with both space charge control and velocity modulation components, said input gap having an electrical length of 211- at the operating frequency for the positive potential applied to said hollow conductive member an anode spaced from the end of said drift space remote from said cathode, a wave guide coupled with said electron beam in the space between said end of said drift space and said anode for deriving electromagnetic energy from said electron beam, and feedback means intercoupling said wave guides for sustaining oscillations in said device.
  • a device system as in claim 10 in which said first recited wave guide is tuned to a predetermined input frequency and said second recited device is tuned to a harmonic of said predetermined input frequency.
  • An electron discharge device system of the type employing an electron beam comprising a cathode for generating a beam of electrons, means providing a drift space the entrance end of which is spaced along said beam a predetermined distance from said cathode, an electron permeable electrode positioned traversing said beam between said cathode and said entrance end of said drift space, electromagnetic wave transducing means connected for high frequency currents between said cathode and said electron permeable electrode to supply high frequency fields for modulating said electron beam with both space charge control and velocity modulation components, the total transit angle of electrons from said cathode to the entrance end of said drift space having a phase angle of about generating a beam of electrons, means providing a drift 24 including a hollow conductive member maintained at a positive potential with respect to said cathode for accelerating said electron beam, an electron permeable electrode positioned traversing said electron beam between said cathode and said entrance end of said drift space, electromagnetic wave transducing means connected for high.
  • each of said electromagnetic wave transducing means comprises a cavity resonator.
  • a device system as in claim 14 in which said electron permeable electrode is maintained at a negative potential with respect to said cathode.
  • a device system as in claim 14 in which said first recited electromagnetic wave transducing means is tuned to a predetermined input frequency and said second recited electromagnetic wave transducing means is tuned to a harmonic of said input frequency.
  • An electron discharge device system of the type employing an electron beam comprising a cathode for generating a beam of electrons, means providing a drift space the entrance end of which is spaced along said beam a predetermined distance from said cathode, said means including a hollow conductive member maintained at a positive potential with respect to said cathode forv accelerating said electron beam, an electron permeable electrode positioned traversing said electron beam between said cathode said entrance end of said drift space,
  • electromagnetic wave transducing means connected for high frequency currents between said cathode and said electron permeable electrode to supply high frequency fields for modulating said electron beam with both space charge control and velocity modulation components, the the total transit angle of electrons from said cathode to the entrance end of said drift space having a phase angle of about fining wall thereof, a cathode positioned within said resonator opposite said opening for generating a beam of electrons which passes through said opening, means providing a drift space for said electron beam having said opening as an entrance end, and an annular cavity resonator coupled with said electron beam at the exit end of said drift space the total transit angle of-electrons from said 25 cathode to the entrance end of said drift space having a phase angle of about with respect to said space charge component.
  • An electron discharge device system of the type employing an electron beam comprising a cylindrical cavity resonator having a peripheral opening in the defining wall thereof, a cylindrical cathode positioned within said resonator opposite said opening for generating a beam of electrons which passes through said opening, an electron permeable grid positioned traversing said beam of electrons between said cathode and said opening such that electromagnetic waves sustained within said cavity resonator modulate said electron beam with both space charge control and velocity modulation in the space between said cathode and said grid, means providing a drift space for said electron beam having said opening as an entrance end, an annular cavity resonator coupled with said electron beam at the exit end of said drift space to extract electromagnetic energy from said beam the total transit angle of electrons from said cathode to the entrance end of said drift space having a phase angle of about with respect to said space charge component.
  • a device system in claim 20 in which said defining wall of said cavity resonator is maintained at a positive potential with respect to said cathode and said electron 26 permeable grid is maintained at a negative potential with respect to said cathode.
  • a device system as in claim 21 in which said electron permeable grid is by-passed for high frequency currents to said defining wall of said cavity resonator.
  • An electron discharge device system of the type employing an electron beam comprising a cathode and generating a beam of electrons, means spaced from said cathode and providing a drift space spaced along said beam from said cathode to provide an input gap, electromagnetic wave transducing means coupled to said electron beam to supply high frequency fields across said input gap for modulating said beam with a space charge control component and a velocity modulation component, the physical length of said gap corresponding to an average transit angle of electrons across said gap of Zn, an anode spaced from the exit end of said drift space, and output electromagnetic wave transducing means coupled with said electron beam in the space between the exit end of said drift space and said anode for deriving electromagnetic energy from said electron beam.

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US265014A 1952-01-04 1952-01-04 High frequency electron discharge device and system Expired - Lifetime US2793316A (en)

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Application Number Priority Date Filing Date Title
BE516737D BE516737A (en(2012)) 1952-01-04
US265014A US2793316A (en) 1952-01-04 1952-01-04 High frequency electron discharge device and system
GB51/53A GB780473A (en) 1952-01-04 1953-01-01 Improvements in and relating to velocity modulation apparatus for the generation andtranslation of electromagnetic waves
FR1073483D FR1073483A (fr) 1952-01-04 1953-01-05 Méthodes et dispositifs pour la production et l'amplification de l'énergie électromagnétique
CH310960D CH310960A (de) 1952-01-04 1953-01-05 Verfahren und Einrichtung für die Erzeugung oder Umsetzung elektrischer Hochfrequenzenergie mittels eines Elektronenstrahls.

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US265014A US2793316A (en) 1952-01-04 1952-01-04 High frequency electron discharge device and system

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BE (1) BE516737A (en(2012))
CH (1) CH310960A (en(2012))
FR (1) FR1073483A (en(2012))
GB (1) GB780473A (en(2012))

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2449965A1 (fr) * 1978-11-24 1980-09-19 Us Energy Amplificateur a haute frequence a faisceau tournant
FR2527005A1 (fr) * 1982-05-12 1983-11-18 Varian Associates Tube electronique de puissance a grille perfectionne
FR2547456A1 (fr) * 1983-06-09 1984-12-14 Varian Associates Tube a faisceau d'electrons module en densite avec un gain accru

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2314794A (en) * 1940-06-25 1943-03-23 Rca Corp Microwave device
USRE22389E (en) * 1940-07-13 1943-11-02 Electron beam concentrating
USRE22590E (en) * 1945-01-16 Boiler conditioning apparatus
US2368031A (en) * 1940-03-15 1945-01-23 Bell Telephone Labor Inc Electron discharge device
US2391016A (en) * 1941-10-31 1945-12-18 Sperry Gyroscope Co Inc High-frequency tube structure
US2425748A (en) * 1941-03-11 1947-08-19 Bell Telephone Labor Inc Electron discharge device
US2484643A (en) * 1945-03-06 1949-10-11 Bell Telephone Labor Inc High-frequency electronic device
US2498886A (en) * 1937-07-14 1950-02-28 Gen Electric Ultra short wave device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE22590E (en) * 1945-01-16 Boiler conditioning apparatus
US2498886A (en) * 1937-07-14 1950-02-28 Gen Electric Ultra short wave device
US2368031A (en) * 1940-03-15 1945-01-23 Bell Telephone Labor Inc Electron discharge device
US2314794A (en) * 1940-06-25 1943-03-23 Rca Corp Microwave device
USRE22389E (en) * 1940-07-13 1943-11-02 Electron beam concentrating
US2425748A (en) * 1941-03-11 1947-08-19 Bell Telephone Labor Inc Electron discharge device
US2391016A (en) * 1941-10-31 1945-12-18 Sperry Gyroscope Co Inc High-frequency tube structure
US2484643A (en) * 1945-03-06 1949-10-11 Bell Telephone Labor Inc High-frequency electronic device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2449965A1 (fr) * 1978-11-24 1980-09-19 Us Energy Amplificateur a haute frequence a faisceau tournant
FR2527005A1 (fr) * 1982-05-12 1983-11-18 Varian Associates Tube electronique de puissance a grille perfectionne
FR2547456A1 (fr) * 1983-06-09 1984-12-14 Varian Associates Tube a faisceau d'electrons module en densite avec un gain accru

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Publication number Publication date
CH310960A (de) 1955-11-15
GB780473A (en) 1957-08-07
BE516737A (en(2012))
FR1073483A (fr) 1954-09-27

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