US2462496A - Electron discharge device - Google Patents

Description

Feb. 22, T1949. l- E. w. HEROLD 2,462,496

7 v ELECTRON DISCHARGE DEVICE I Filed April 24, 1942 2 sheets-sheet 1 Fig 1.

INVENTOR ATTORNEY ZQww/w gamma make/m2;

E; w. HE ROLD ELECTRON DISCHARGE DEVICE Feb. 22, 1949.- 2,462,496

Filed April 24, 1942 2 Sheets-Sheet 2 fso INVENTOR braid "9791mm Patented Feb. 22, 1949 ELECTRON DISCHARGE DEVICE Edward W. Herold, Verona, N. J., assignor to Radio Corporation of America, a corporation of Delaware I Application April 24, 1942, Serial No. 440,283

17 Claims.

My invention relates to electron discharge devices, more particularly to such devices utilizing beam deflection and suitable for use at very high frequencies.

In conventional tubes of the type under consideration a beam of electrons is directed between a pair of deflectin electrodes toward an apertured electrode behind which is usually placed a collector. Alternating radio frequency voltages are applied to the deflecting electrodes to cause the electron beam to be deflected across the aperture in the apertured electrode to thus control the amount of current flowing to the collector, which may be used as an output electrode. At frequencies above 600 megacycles per second it becomes diflicult to obtain high transconductance because of the transit time effects resulting when the transit time of the electrons between the plates is equal to an appreciable part of a period of the applied radio frequency voltages. It has been found best to make the deflecting plates with a dimension in the direction of travel of the electron beam substantially equal to the distance travelled by an electron during a half period of the applied controlling voltage, or the electrical length is 1r radians, as expressed in the transit angle on.

This may best be explained by the following illustration: Assuming that the deflecting plates between which the electron beam is directed are comparatively long and that a high frequency signal is applied to the plates, an electron which enters between the plates at the beginning of the cycle will be deflected in one direction, but before it has travelled to the end of the plates the high frequency electric field will be reversed so that deflection is reduced. As a result the electron may leave the space between the plates with little deflection. However, if the time which the electron spends between the plates, or the transit time of the electron between the plates, is equal to a half period of the applied voltage, the deflection of the electron will always be in the same direction and will be a maximum, since the electron leaves the space between the plates before reversal of the field takes place, which occurs every half period of the high frequency signal. The maximum length of the deflecting plates therefore should be such that electron transit time is about one-half period.

Expressed mathematically, if 1- is the transit where T is the period, and j the frequency of the high frequency signal. The electrical angle tor of the high frequency signal before it reverses phase is equal to 1r, so expressed in angular form the above relation becomes 21rf1=w'r, which is equal to 1|- and it may be said that the electrical length of the deflecting plates should be 11' radians, as expressed in the transit angle arr,

While it has been found that maximum deflection will result when the dimension of the deflecting electrode in the direction of travel of the beam is equal to the distance travelled by an electron during a half period, at the higher frequencies the time spent by an electron between the deflecting plates becomes increasingly small so that the amount of deflection also decreases since each individual electron is subjected to deflection field for a shorter period of time.

Attempts have been made to increase the deflection sensitivity or the transconductance of the tube by multiple deflection brought about by a plurality of successively positioned oppositely disposed deflecting elements cross connected. This arrangement, however, is open to the objection that the D. C. or static deflection is lower than the dynamic high frequency deflection, that is the tube is difficult to test and in addition the in the electrodes and leads.

structure required is not simple and does not lend itself readily to mass production.

In addition, due to accidental factors, such as possible space charge, misalignment and like factors, the phase relationship of the controlling voltage on the deflecting plates to the deflected beam may not be such as to produce with optimum results the additive deflection sought. In other words, while the phase angle of the deflecting voltage on one pair of plates may be proper for maximum deflection, the voltage on the next pair of deflecting plates may have a phase relationship leading or lagging that required for additive deflection. As a result of the out-of-phase relationship, the second pair of plates may not deflect the same group of electrons to the same extent as a preceding pair of plates or a succeeding pair of plates.

In tubes intended for operation at ultra high frequencies, the conventional input circuits usually employed are subject to low resonant impedance resulting in an excessive amount of power being required to drive the tube. This decreases the effective gain of the tube operated, for example, as an amplifier. Causes of such high input loading include, among other things, ohmic and radiation losses due to high circulating currents The usual output circuit does not have the desired high impedance for producing maximum output voltages so that voltages developed in the output do not reach the values they would otherwise have, thus reducing the efiectiveness of the device.

It is an object of my invention to provide an electron discharge device of the beam deflection type whichsis particularly suitable .for use; at high frequencies and which has a comparatively high transconductance.

It is another object of my invention to provide an improved device of the type described utilizin multiple additive deflection and of asimp1e me chanical construction. 7

.A still further object of. myeinvention is :to provide an electron discharge device of the multiple deflection type, in which pro-perphase relationship of the electron beam arid'the-radio frequency controlling voltage exists to insure optimum operation.

It is.-.another.object of my invention to provide such. an electron, discharge device utilizing low lossehighimpedance circuits, thereby, increasing .theefiectiveness of the input controlling voltages 1.an'd-ava'ilable..output voltages for givencondh .tions.

The novel features .whichlbelieve. to be characteristic ..of .my. invention are. set forth with particularity in-theappended claims, but the invention itself .will bestbe understood by. refer- .ence. to the followingdescription taken in .con- .nection .With ..the accompanying drawing .in whichfEigurcllis along-itudinal. section of an electron discharge-device made according to my .iinvention and .its lassociatedccircuit, -Figures .2 ;.and .3 are enlarged :cleta-ils of construction of; the device shown inFigure I, Figure .4. isa longitlidinalschematic .view. of a. modification of the a. device shown-in Figure 1 with .a phase. adjusting -,circuit.;attachment,Figure .5 is a schematic .longitudinalisection. of still another or-m 'oimy .zinvention utilizinglow. loss-high impedance ..cir- .-.-cu-its;-.F igure dis .a sch matic longitudinal-section sand partial:perspective or a still further.- modi -r-ficati-onlof: my -invention and Figure 'l-isa section @Qf figure-.6 showing-details otconstructiou.

-Referring .to .Figure 1,.an :electrondischarge device made according to my .invention 1 com prises they-evacuatednenvelope it containing. the :ousual. press l l and base i2. sSupported from the .press Joy. means ofsupport :andUlea-d wires are. the indirectly heated cathocle-t3= and beam iorming --electrode M, .the relative. positions of which. are shown; in -'-Figure .3. --Mounted atztheotherend f! the envelope. I0 is the'collector l5. Positioned -.-between-. the cathode and collector is-the beam ;deflecting system comprising the tubular mem- ..-ber.:l'6-:havingaplurality of transverse: partition- --1likeielements 51,48 and t9 providedwith aligned iapertures l'1,,"l8 and 1-9. A conducting element .ai-Ir the-form 'of a 'rod 2il--ex-tends longitudinal-1y .ot the aperture -l 9- asshownzFi-gurefi to .provideiardoubleaperture so that the desired-control voltage anode current characteristic isobtained.

@Imaccordancewith my, invention, between the transverse elements iS- a-nd-lS are aplurality-of =success-ively positioned-pairs ofdeflecting :elec- "strodes l Irand 22,= the elementson thesame side =--.of :t-her-pathrof the-electron beam. between cath- .-ode' l3 land collector being: electrically con- .-nected together.- and supported by thesame supuportuand lead wires. -Ifhe. distance betweenthe -..centers..of.-tl1ese electrodes. is equal to the. distance .travel 1e'd.-.by an electron .during. a full pe- .-rind,oilthe.applieddeflecting voltage. The result of this arrangement is to produce successive additive deflection of the electron beam. Preferably the dimension of the deflecting electrodes in the direction of travel of the electron beam is equal to substantially a half period although this dimension is not critical. A pair of Lecher wires 23 shorted by the shorting bar 24 provides the inputcircuit to which'signal input voltage :and localoscillator voltage may both be applied to produce an intermediate frequency voltage "i I in the output circuit, which is connected between collector l5 and tubular member IE, and comprises output transformer 25 and lay-passing condenser 26, the condenser 26 permitting difierent D. C. voltages to be applied to the collector is and to the: tubular member it. The collector 15 .may be coated with secondary emitting material, the secondary'electrons being collected by part1 .tion 19 or the primary electrons may be absorbed by the collector l5 without any secondary emission amplification. -The source of voltage and divider arrangement. 22' permits the relative voltages on deflecting elements 2i and 22 to be adjusted so that the beam, with no radio frequency or oscillator voltage on the plates, will be directed gyatxtherod 28 to center it with respect to the electrode system.

:In operation electrons from the indirectly heated cathode iii are formed into a beam and directed through apertures H and $8 in eleso. ments ii and it, which lastelement in combinaztion with the deflecting element 2i may be arranged to provide an electron lens arrangement :for providing a sharply focused beam on the rod iii. The electrons in passing through elements i3 and i9 must pass between the deflecting ele- --ments-2l and 22, the centers of the successive pairs of which are spaced a distance apart equal to the distance travelled by an electron during a whole period. Thus, an electron which is demflectedeupwardly between'the first set of plates linand-22-willagain be deflected upwardly between the second set. of plates 2i and 22, since the-phase relationship of the voltage on the deflecting plates with respect to the electron ifiwthe same between each pair of plates since a whole period is required for the electronto travel from-any point between one-pair of plates to a similar point between the next pair of deflecting plates. Thus thedeflection is amplified. The electron beam in being deflected across aperture 219' and rod 255 has the efiect of passing through double apertured electrode so that the electron current with repect to deflecting voltage de- "creases to substantially zero when the beam is 5:3 directed on rod 28 and rises on either side of the -minimum to-a maximum and again to zero depending upon the angle of deflection.

Thus with the arrangement shown support .for the deflecting elements'is simplified because so: all deflecting elements on one side of the beam path can be connected together. The transconductance or deflection sensitivity is increased by .-insuri-ng successive additive deflection. It is, of course, obvious that more than 'two pairs of 55 deflecting elements could be used for the purpose of bringing about additive deflection.

In Figure 4 I show an arrangement whereby ithe need for spacing the centers of the pairs of deflecting elements predetermined distances :4; determined by the frequency of operation is unnecessary. As here shown the envelope 30 contains cathode 3i, beam forming electrode 32 and collector 33. The deflecting electrode system includes tubular .memvber. 35, which is provided 7.; with aperturedtransverse partitions 35,'36 and 31, the last aperture being provided with the rod 38 which bisects the aperture longitudinally to produce a double aperture to bring about the desired control voltage-output current characteristic. Successive pairs of deflecting elements 39 and are positioned between elements 36 and 31. These electrode elements may be connected to Lecher wire systems 4! and 42 to which the oscillator and signal voltages may be applied.

In order to insure that a proper phase relationship exists between the beam passing through the deflecting electrode system and the controlling voltages on the deflecting elements, a phasing arrangement including a trombone tuning element 44 is connected between the two Lecher wire systems. By proper adjustment the coupling between the two deflecting systems may be varied as to length so that the signal and oscillator voltages may be fed to the Lecher wire systems in proper phase to produce maximum additive deflection between each pair of the deflecting elements, regardless of the spacing between pairs of deflecting elements. This simplifies manufacturing construction and also provides means for compensating for irregularities and accidental factors in construction and operation of the tube.

In order to increase further the efficiency of the tube disclosed, it is possible to utilize circuits having high resonant impedances, such for example as resonant cavity circuits or so-called resonators.

In Figure 5 is shown a modification of an electron discharge device utilizing my invention. In this form a pair of resonators are used for producing additive deflection in combination with the phasing arrangement shown in Figure t. The envelope contains at one end cathode means 5! for providing a directed beam of electrons and at the other end a collector 52. The deflecting system comprises tubular elements 53 and 56, and a pair of resonators 54 and 55, each of which is provided with opposed deflecting elements 5B and 55 and 6E! and El positioned within the resonators, one element of each pair being connected to an opposite wall. As is well known the resonators may be set into oscillation, and in one mode of operation an alternating voltage can be made to appear between the opposite Walls of the resonator at the apertures, the elements 53 and 59, for example, assuming the voltage of the side of the resonator to which it is attached so that a transverse electrostatic field appears between the deflecting elements to deflect the beam of electrons laterally during operation of the device. To insure a properly directed beam 1 may employ a pair of beam directing elements 5'! positioned between the apertured partition 53' and one Wall of the resonant cavity circuit 55. The second resonator 55 is provided with apertured member 62, provided with the rod-like connecting element 54 to provide a double aperture. A voltage source and divider arrangement permits the proper biasing voltages to be applied to beam directing elements 51. The output is taken between resonator 55 and collector 52 by means of the output circuit including transformer 56 and by-passing condenser 51, the voltage source 59 providing the necessary biasing voltages. between the electron beam and the voltages appearing on the deflecting elements 58 and 59, and 6B and 6! I again employ a trombone method of tuning using slide 58 to vary the length of the coupling circuit and hence controlling the To insure proper phase relationship phase relationship of the voltages appearing between the pairs of deflecting elements and the electron beam.

A still further modification of my invention is shown in Figure 6 employing a four-wire transmission line. In this arrangement the envelope it has positioned at one end the cathode H and beam forming element i2, which may be electrically connected to the cathode lead. The collector T3 is positioned at the other end of the envelope and the deflecting system is positioned between the cathode and collector. The deflecting system includes tubular member 14 provided with apertured transverse elements l5, l6 and ii. The pairs of deflecting electrodes 18 and T9 are positioned between transverse elements 16 and l? and are connected to transmission line comprising elements 89 and 8! shorted by shorting bar 82 which may be positioned so that the distance from the plates to the shorting bar is equal to one-quarter or three-quarters of a wavelength. The input voltage may be applied as indicated, the two sides of the lines being cross connected by means of conductors 84 and 53 so as to bring about a proper phase relationship of the radio frequency Voltages appearing between the deflecting elements. To permit proper biasing potentials to be applied to the deflecting elements 78 and 15, conductors 88, 89, 95 and 5| extend through tubular elements and iii, the elements Eli and 8! being connected to deflecting elements 18 and 19 for radio frequency by means of coupling condensers such as 85 and 85. Voltages for applying proper D. C.

Y potentials to the deflecting elements are obtained from voltage source 81. With the arrangement shown the D. C. static characteristics of the device may be examined by changing the connections to the deflecting elements.

While I have indicated the preferred embodiments of my invention of which I am now aware and have also indicated only one specific application for which my invention may be employed, it will be apparent that my invention is by no means limited to the exact forms illustrated or the use indicated, but that many variations may be made in the particular structure used and parting from the scope of my invention as set forth in the appended claims. the purpose for which it is employed without de- What I claim as new is:

1. An electron discharge device having a cathode for supplying a beam of electrons and a collector for receiving said electrons, and an apertured member positioned between said cathode and collector throughwhich said beam of electrons may be directed toward said collector, and deflecting means positioned between the cathode and apertured member and including a plurality of successive pairs of oppositely disposed deflecting elements between which the beam of electrons is directed, said deflecting elements of each pair being adapted to have an alternating potential of high; frequency applied therebetween, said pairs of deflecting elements being spaced along the path of travel of the electron beam and means coupled with said deflecting elements for adjusting the phase relation-ship of the applied voltage on each pair of deflecting elements to provide optimum additive deflection of said beam of electrons.

2. An electron discharge device having a cathode for supplying a beam of electrons and a collector for receiving said electrons, and an apertured member positioned between said cathode wpairs ofqdefiecting elements being spaced along ithepath of travel of the electron beam and a rphasejcontrol circuit connected between successive pairsofdeilecting elements for adjusting the phase relationship of the applied voltage on each pair-ofdeflecting elements to provide optimum additive 1 deflection of said beam of electrons across the apertured element.

5-3,;An electron discharge device having a cathtode for supplying a beam of electrons and a colelector for receiving said electrons, deflecting qmeansposition-ed between the cathode and colj' le'ctor and including a plurality of successive pairs -;-.of-,opposite ly disposed deflecting elements be- .tween which the beam of electrons is directed,

Eancladapted to have analternating potential of Ihighfrequencyapplied between the elements of "each pair, all-of the deflecting elements on one -side of-the beam path lying in one plane and allitheudeflectingelements on the other side of the beamv pa-thlying in a plane parallel to the 'flrstplane, transmission line means connected -;hetw een the successive pairs of oppositely dis- "posed deflecting elements and means coupled to said transmission line for varying the length of said transmission line 'for determining the phase i relationship of the alternating potential of high frequency on said deflecting elements with respect to the beam of electrons to provide optimum additive deflection of said beam of electrons.

4. An electron discharge device'having a cathcdeforlsupplying a beam of electrons and a collector for receiving said electrons, deflecting ---means positioned between the cathode and collectorand including a plurality of successive pairs of oppositely disposed deflecting elements between which the beam of electrons is directed and adapted to have an alternating potential of high frequency applied between the elements of each pair, conducting means surrounding said deflecting elements, said conducting means having aligned apertures through which the beam of electrons is directed, a transmission line coupled between successive pairs of oppositely ldisposed deflecting elements for applying an alteri nating potential of high frequency to said ele- -ments, and means coupled to said transmission line for varying the length of said transmission line for determining the phase relationship of the alternating potential on said deflecting ele ments with respect to the beam of electrons to provide optimum additive deflection of said beam of electrons.

5. An electrondischarge device having a cathode forsupplying a beam of electrons and a collector for receiving said electrons, deflecting means positioned between the cathode and collector and including a plurality of successive pairs of oppositely disposed deflecting elements between which the beam of electrons is directed and adapted to have an alternating potential of high frequency applied between the elements of -:-each--pair,alldeflecting elements on one side of e -beam :path lying in-one plane and all de- ,fiecting-elementsonetheother side of,;the beam 58 path lying in-av plane parallelto the first plane, conducting means surrounding said deflecting elements, said conducting means havingaligned apertures through which the beam of electrons is vclirectedpand a tuned transmission line con- 'nected to each of said pairs of deflecting eleoptimumadditive deflection of said beam of electrons.

16. An electron discharge device having a cathode for supplying a beam of electrons and a collector for receiving said electrons, and deflecting means positioned between said cathode and collector and including a plurality of successive hollow conducting members having apertures through which the beam of electrons is directed, deflecting elem nts separate from the Wall of said hollow conducting members and positioned within each of the hollow conducting .-=e nbers and connected to the Walls .of said cong members adjacent the apertures for rea high frequency alternating potential .n, and between which the beam of electrons is directed for laterally deflecting said beam of electrons, and a coupling transmission line connected between said hollowlconducting members and adapted to have an alternating potential of high frequency applied thereto for ensaid hollow conducting members, and

means coupled to said coupling transmission line for varying the length of the coupling transmission line for determining the phase relationship or the alternating potential on said deflecting elements.

'7. An electron discharge device havinga cathode for supplying a beam of electrons and a collector for receiving said electrons, a pair of successively positioned resonators positioned in the beam path and having apertures aligned with the beam path for permitting the beam to pass through said resonators, and deflecting elements separate from the walls of said resonator positioned within each of said resonators and elec trically connected to and supported by opposite walls of said resonators adjacent the apertures a coupling circuit connected between said resonators and adapted to have a controlling alternating potential of a high frequency applied to said coupling circuit for energizing said reso- Ira-tors, and means coupled to said coupling-cincuit' for varying the coupling circuit for controlling the phase relationship of the high frequency alternating potentials on said deflecting elements with respect to said beam of electrons.

8. An electron'discharge device having a cathode for supplying a beamof electrons and a collector for receiving said electrons, a pair of successively positioned resonators positioned in the path and having apertures aligned with the beam path for permitting the beam-to pass through said resonators, and-deflecting elements separate from and transverse to the walls of said resonators and positioned within each of said resonators and electrical y connected to and supported by opposite walls of each of; saidresopato s adiece th a er ures; f subjecting t electron beam to lateral deflection, a transmission line coupling circuit connected between said resonators and adapted to have a controlling alternating potential of a highfrequency applied to said transmission line for energizing said resonators, and means coupled to said transmission line for varying the length of said transmission line, and means between the cathode and the first of said resonators for directing the beam of electrons through said resonators.

9. An electron discharge device having a cathode for supplying a beam of electrons and a collector for receiving said electrons, a pair of successively positioned resonators positioned in the beam path and having apertures aligned with the beam path for permitting the beam to pass through said resonators, and deflecting elements separate from and transverse to the walls of said resonators and positioned within each of said resonators and electrically connected to and supported by opposite walls of each of said resonators adjacent the apertures for subjecting the electron beam to lateral deflection, a coupling circuit connected between said resonators and energizing said resonators,

10. An electron discharge device including a cathode for supplying a beam of electrons, and

:a collector for receiving said electrons, and means positioned between the cathode and collector for periodically deflecting the beam of electrons, and including a plurality of pairs of successively positioned deflecting elements, all of the deflecting elements on one side of the 'beam path lying in one plane and all deflecting elements on the other side of the beam path lying in a plane parallel to the first plane, conducting mean-s surrounding said deflecting elements and having oppositely disposed apertures through which the beam of electrons is directed, and a transmission line connected between the elements of each pair of deflecting elements, said transmission line including a pair of parallel conductors, and mean-s slidable longitudinally of the transmission lines for Varying the length of the transmission lines, and means electrically cross-connecting the conductors of the transmission lines.

11. An electron discharge device including a cathode for supplying a beam of electrons, and a collector for receiving said electrons, and means positioned between the cathode and collector for periodically deflecting the beam of electrons, and including a plurality of pairs of successively positioned deflecting elements for additively deflecting the beam of electrons in the same direction, means disposed between the collector and deflecting mean having an aperture through which the beam of electrons is directed, and a transmission line connected between the elements of each pair of deflecting elements, each of the transmission lines including a pair of parallel conductors, and a common conducting means shorting all of said conductors, and means electrically cross-connecting the conductors of the transmission lines for applying input voltages in proper phase on said pairs of deflecting elements.

12. An electron discharge device including a 10 cathode for supplying a beam of electrons, and a collector for receiving said electrons, and means positioned between the cathode and collector for periodically deflecting the beam of electrons, and including a plurality of pairs of successively positioned deflectingelements means disposed between the collector and deflecting means having an aperture through which the beam ofelectrons isdirected ,v and a transmission line connected between the elements of each pair of deflecting elements, each of said transmission lines including a pair of parallel conductors, all of said conductors being parallel to each other and conducting means engaging all or said par- -.l conductors and movable longitudinally; thereof for simultaneously tuning both of said transmission lines and means connected to the transmission lines for applying an alternating voltage of high frequency to said transmission lines.

13. An electron discharge device having a cathode for supplying a beam of electrons and a collector for receiving said electrons, and deflecting means positioned between the cathode and collector and including a plurality of successively positioned hollow conducting members having apertures through which the beam of electrons is directed and deflecting elements positioned within and separate from the walls of each of the hollow conducting members and connected with the walls of said hollow conducting member-s adjacent the apertures for receiving a high frequency alternating potential thereon and etween which the beam of electrons is directed for laterally deflecting said beam of electrons.

14. An electron discharge device having a cathode for supplying a beam of electrons and a collector for receiving said electrons, and deflecting means positioned between the cathode and collector and including a plurality of successively positioned hollow conducting members having apertures through which the beam of electrons is directed and deflecting elements positioned within and separate from the walls of each of the hollow conducting members and connected with the walls of said hollow conducting members adjacent the apertures for receiving a high frequency alternating potential thereon and between which the beam of electrons is directed for laterally deflecting said beam of electrons, and coupling means connected between said hollow conducting members and adapted to have an alternating potential of high frequency applied thereto for energizing said hollow conducting members.

15. An electron discharge device having a cathode for supplying a beam of electrons and a collector for receiving said electrons, and defleeting means positioned between the cathode and collector and including a plurality of successively positioned hollow conducting members having apertures through which the beam of electrons is directed and deflecting elements separate from the walls of and positioned within each of the hollow conducting members and connected with the walls of said hollow conducting members adjacent the apertures for receiving a high frequency alternating potential thereon and between which the beam of electrons is directed for laterally deflecting said beam of electrons, and coupling means connected between said hollow conducting members and adapted to have an alternating potential of high frequency applied thereto for energizing said hollow conducting members, and means coupled to said coupling 7 11 means for varying the'coupling means for determining the phase of the alternating potential on said deflecting elements.

- 16. An electron discharge device including a cathode for supplying a beam of electrons and a collector for receiving said electrons, and means positioned between the cathode and collector for periodically deflecting said beam of' electrons and including a plurality of pairs of successively positioned deflecting elements, the elements of each pair of successively positioned deflecting elements lying inthe same plane to deflect said beam of electron-s in the same plane, conducting means surrounding said deflecting elements and having oppositely disposed apertures through which the beam of electrons is directed, a transmission line connected between the elements of each pair of deflecting elements, each transmis- 'sion line including apair of'parallel conductors,

mean-s'terminating the transmission lines, and means connected to the transmission line for applying an alternating voltage of high frequency to said transmission lines.

17.An electron discharge device having a cathode for supplying a beam of electrons and an electrode toward which said electrons are directed, an apertured member positioned between said cathode and said electrode and through which the beam of electrons may be directed toward said electrode, and deflecting means positioned between the cathode and apertured member and including a plurality of successive pairs of oppositely disposed deflecting 1' 2 elements through which-the beam of electrons is directed andadapted to have alternating po: tential of: high frequency applied between'the' elementsoieachpairgcircuit means connected between thed'iiectingelements' of each pair and means coupied withlsaid circuits for adjustingthe phase relatiehshipof the applied voltage on eachpairoi deflecting elements to provide an optimum added -deflection for said beam of electrons.

EDWARD W. HEROLD.

REFERENCES CITED The following references are of record in the file of this patent:

. UNITED STATES PATENTS

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