Get. 15, 39%. - .1. A. MORTON 2,499,222 ELECTRON DISCHARGE DEVICE Filed July 19, 1941 ' 4 Sheets-Sheét 1 FIG. / Il l lglilil l l FIG. 2 ' INVENTOR .1 AMOR TON 8” 1.1M ATTORNEY ELECTRON DISCHARGE DEVIC‘E Filed July 19, 1941 ‘.36 4 Sheets-Sheet 2 ‘ HEQ/lélglil l l l? FIG 3 3/ HF. LOAD FIG. 4 TING FREQUENCY |l|||i|||| [11ml IIIIIIIIIIIIIIIIH] INVENTOR BY J A. MOR TON ATTOQAEV Get. 35, 1M6. J. A. MORTON ELECTRON DISCHARGE DEVICE Filed July 19, 1941 4 Sheets-Sheet 3 _Em: ___ ,_ _ m_ mm. INVEN 7'01? ‘1; AMI? TO/V BV A 7' TORNEV Qt“ 15, 1946» ' J. A. MORTON 2,409,22 ELECTRON DISCHARGE DEVICE Filed July 19, 1941 4 Sheets-'She'et 4 A FIG. 6 FIG. 7 99 i INVEN TOR Patented Oct. 15, 1946 2,409,222 UNITED‘ STATES PATENT OFFICE ' 2,409,222 ' ELECTRON DISCHARGE DEVICE Jack A. Morton, Upper Montclair, N. J.,_ assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y.,_a corporation of New York Application July 19, 1941, Serial No. 403,119‘ '19 Claims. (Cl. 315-5) 1 ' . v This invention relates to high frequency elec tronic devices of the so-called magnetron type. An object is to secure improved efficiency of operation and higher energy output from such devices at very high frequencies. ' I Another object is to make less critic'al‘the op 2 anode, between sections of the anode or between separate electrodes adjacent to the anode. Some of the electrons enter the high frequency ?eld at a period of the cycle to absorb energy and be accelerated so as to strike the anode and be re moved from the interaction space. Other elec erating adjustments required. trons enter the high frequency ?eld at a period Another object is to pregroup the electrons and of the cycle to give up energy and be retarded so avoid losses occasioned by the collection of that their path avoids the anode and they con energy-absorbing electrons on. the plates of the 10 tinue along a helical path giving up energy to the ?eld and the associated high frequency cir Another object is to provide such a device in cuit during periods of interaction in successive which the cathode is removed from the region of cycles. Due to the preponderance of energy the high frequency ?eld, thus avoiding electron giving periods of interaction between electrons bombardment and the instabilities of so-called and the high frequency ?eld on account of the magnetron. _ . ' back heating. Another object is to make the device applicable to ampli?er as well as oscillator circuits. Another object is to utilize the magnetron, with its characteristic of providing repeated in early elimination of energy-absorbing electrons the net result is the generation of energy in the attached high frequency circuit. The necessity for prompt elimination of the energy-absorbing electrons so that the effect of teractions between the electrons and the high the energy-giving electrons will predominate in frequency ?eld, as a unilateral ampli?er. troduces limitations of the conventional type of Another object is to incorporate with the device magnetron which are largely overcome by this e?icient non-radiating circuits. invention. This is accomplished by introducing Another object is to provide such a device 25 the electrons in a stream from a source external readily adaptable to operation at various fre to the space where interaction takes place be quencies and easily coupled to external circuits. tween the electrons and the electric and mag Another object is to avoid the limitations of netic ?elds and also by converting most ‘of the excessively small tube and circuit elements such electrons into useful, energy-giving electrons by as are encountered in very high frequency opera 30 grouping them before they enter the interaction tion of magnetrons of conventional type. space. By these means less critical adjustment Another object is to adapt the magnetron to for operation is required, more e?icient operation use in a circuit where the generation of a large is attained, all of the electron emission may be amount of output power is to be controlled by a usefully employed and also advantage is had in small amount of control energy. The so-called magnetron is a well-known type ' of device for the generation of high frequency energy. It usually incorporates essentially a cathode, an anode surrounding the cathode and that there is no longer a. cathode in the interac tion space with the attendant di?iculties due to electron bombardment of it. The principles of the invention are applicable to magnetron structures utilizing electrodes con a static magnetic ?eld parallel to the axes of the 40 nected. to an external circuit or to structures in cathode and anode. The electron path is de which the high frequency circuit is a resonant viated from a, straight line by action of the mag cavity or a portion of wave guide. It is also ap-. netic ?eld which is superposed upon the electric plicable to such devices used as oscillators or in ?eld between the cathode and the positively ampli?er arrangements. charged anode. The two ?elds are at substan 45 The various features of the invention will be tially right angles, though to produce desired more fully understood from the following de axial movement of the electrons either the mag tailed description of the illustrative embodiments netic ?eld is tilted so that the angle is slightly shown in the accompanying drawings. different from a right angle or a supplementary In the drawings: axial electric ?eld is provided. In either case the electrons are constrained to follow a curved spiral or helical path due to the combined action of the ?elds. The electrons move also in a high Fig. 1 illustrates for descriptive purposes a con ventional type of magnetron; Fig. 2 shows a magnetron conventional as Fig. 1 in some respects but modi?ed to incorporate fea frequency ?eld produced by a high frequency cir tures of the present invention; cuit connected either between the cathode and 55 Fig. 3 is a modi?cation of Fig. 2 to show high 2,409,222 high frequency wave-length in centimeters cor responding to the frequency of operation and H is the magnetic ?eld strength in gausses. Also, Fig. 4 shows-a high frequency generator using the anode voltage must be adjusted in relation to a tube incorporating crossed electric and mag the above magnetic ?eld strength to establish the netic ?elds and a coaxial type output circuit, critical grazing condition for the electrons, that with modulation by space charge control; is, such that with no high frequency electric ?eld Fig. 5 is similar to Fig. 4, ‘but shows an ampli the electrons following the helical paths will just ?er arrangement with coaxial type input and avoid striking the anode. With high frequency output circuits'with pregrouping of electrons at " 10 energy ?owing in the lecher system connected to high frequency by space charge control; the- anode portions :2 and ‘3 a high frequency Fig. 6 shows as a modi?cation of Fig. 5 an am ?eld is superposed in the space between anode pli?er arrangement similar to that of "F18. 5 ex portions and the electrons interact with that ?eld cept that the pregrouping ofv electrons is accom also. Electrons entering the interaction space plished by the method utilizing electron velocity 15 during one phase of the high frequency ?eld will variation and drift space; and be accelerated and constrained to pass to the Fig. 7 shows a magnetron arrangement accord anode and ‘be collected while those entering that ing to the invention in which'interleaved split space during the opposite phase will‘ be retarded plates are employed, these being tuned by a and constrained to avoid collection at the anode closed resonant output cavity attached thereto. and follow paths similar to I3. Since the re Fig. 1 shows a conventional type of magnetron tarded electrons give up energy to the high fre and circuit. The magnetron is of the so-called quency ?eld during each traversal of it and as split plate type in which the plate or anode sur they'make more traversals of the ?eld than do rounding the ?lamentary cathode I is split into frequency excitation from an external source such as in ampli?er operation; the energy-absorbing electrons which are soon two sections 2 and 3 which are maintained at the same direct potential, but on account of being 25 collected at the anode the net result is a transfer of energy from the moving electrons to the high connected to opposite sides of the high frequency frequency ?eld and a consequent sustaining of circuit composed of the lecher system 9, I0 and II, differ in phase of high frequency potential by 180 degrees. The cathode I and anode 2, 3 . the high frequency energy in the lecher system 9, I0, II. Fig. 2 shows a magnetron similar to that of Fig. l but modi?ed to incorporate features of the pres ent invention. The ?gures are made similar to indicate clearly the added features. In Fig. 2 the enclosing envelope 4 includes an electron gun source 6 through the choke inductance 8 and the apart from the electrodes 2, 3 and the interaction lecher system 9, I0 and II which is connected space therebetween. The source of electrons I to the‘ anode portions 2 and 3 and constitutes the is now the cathode of the electron gun, and well high frequency circuit. A static magnetic ?eld removed from the interaction space. It is heated with lines of force parallel to the axis of the indirectly from potential source ‘I. Electrons cathode and anode is ‘produced in the space be tween the cathode and‘ anode by the solenoid 40 from the cathode I are accelerated to the right through the grids 23 and 24 and toward collector winding 5. This devicev operates in the well 20 by the accelerating electrode 2|, 22, This ac known manner as has already been described celerating electrode is preferably, though not es brie?y. Electrons from the cathode I are drawn sentially, of the composite type as shown. The toward the anode 2, 3 by the electric ?eld .due to are enclosed in an evacuated space by the en 30 velope 4. The cathode I is heated by potential source 1 and the anode 2, 3'is polarized positively with respect to the cathode by the potential ' the anode being polarized positively with respect 45 composite electrode encircles the electron path and is made up of two interleaved portions of to the cathode. The magnetic ?eld due to coil 5, conducting material whichv are insulated from each other and charged to different potentials. instead of following straight paths to the anode The surface areas of the two portions of mate they follow curved paths similar to those indi cated by the dotted lines I2 and I3. If a path, 50 rial exposed to the electron stream vary along the direction of the electron path, the exposed areas such as I2, is followed the electron is immediately of the two portions preponderating in opposite collected by one of the anode portions 2 or 3. however, acts on the moving electrons so that directions so that a uniform electrostatic ?eld is If a path, such as I3, is followed the electron produced in a direction depending upon the rela does not reach the anode immediately and after making one or more loops may return to the vi 55 tive polarities of the two portions. The portions 2i and 22 are connected to the polarizing poten cinity of the cathode. Whether, without high fre quency voltage on the plate segments, the path tial sources 6 and 25 so that 2| is the more posi tive causing the accelerating ?eld to be directed followed is similar to I2 or to I3 depends upon the relative adjustments of the anode polarizing from cathode I toward collector 20. The poten ‘potential and the magnetic ?eld due to the coil 5. 60 tial source 25 is provided in conjunction with In a perfectly symmetrical arrangement’as shown source 6 so that‘ electrode portion 22 may be po larized either positively or negatively with respect in Fig. 1 the electron paths will lie in planes per to the cathode I for the purpose of focusing the pendicular to the axis of the'tube. If the static magnetic ?eld due to coil 5 is tilted to be at an electron stream. The electrodes 2 and 3 are angle to the axis of the cathode and anode or 65 polarized positively with respect to the cathode if the electrons are given a longitudinal compo by means of source 6, the connection being made through choke inductance 8, the lecher system nent of direction, the paths will become helical and progress along the axis as indicated at I3 crossbar II and the lecher wires 9 and Ill. The high positive potential of electrodes 2 and 3 in Fig. 1. As is well known, the magnetic ?eld must be adjusted to an intensity such that the 70 causes the electron stream to diverge after pass ing the grids 23 and 24 so that the electrons enter precessional frequency of the electrons along the helical paths corresponds to the frequency of the interaction space between 2 and 3 directed at ' an angle to the axial magnetic ?eld produced by operation, i. e., the product AH should be a con coil 5. This positive diverging potential of 2 and stant, approximately 13,009 when using the two segment plates as shown in Fig. l, where A is the 76 3 and the axial magnetic ?eld are adjusted so ' 2,409,222 5 that the electrons travel helical paths of a preces-= sional frequency equal to the resonant frequency of the external high frequency circuit, which in Fig. 2 is the tuned lecher system 9, l0 and II. Obviously, the phase lens may be'energized from an external source of high frequency rather than from the lecher system associated with the tube, thus providing an ampli?er system. Such The grids 23 and 24 constitute a phase lens which an arrangement is shown in Fig. 3. Pregrouping is energized from the lecher system, and a suit of electrons is obtained just as in Fig. 2 and the able drift space is allowed between the phase lens operation is generally similar with the exception and the ?eld space between electrodes 2 and 3 to that adjustments must be made to avoid the pro allow grouping or bunching of the electrons to duction of oscillations through plate sorting due occur, 10 to the collection of a portion of the electrons by In operation, the electron stream from the cath the'plate segments 2, 3, when there is no high fre ode I, the path of a portion of which is indicated quency input. An external high frequency source by the dotted line 28, is accelerated by the com 35 is shown connected to the input lecher system posite electrode 2|, 22, passes through the phase through the movable members 36 and 31 and the lens 23, 24, is then made divergent by the high 15 output load, indicated as a resistance 38, is shown positivepotential on electrodes 2 and 3 and then connected to the output lecher system through passes through the ?eld, or interaction, space be the movable members 39 and 40. tween electrodes 2 and 3 where the axial magnetic Fig. 4 illustrates an embodiment of the inven ?eld causes the electrons to follow helical paths. tion utilizing a coaxial type of output circuit com The electrons are ?nally collected at the posi 20 prising portions of the electron tube. In this tively charged collecting electrode 20. In passing ?gure, | is an electron emitting cathode indi between the grids 23 and 24 of the phase lens, rectly heated from source 1. ' The cathode is the electrons are subjected to a high frequency connected to and supported by the ring 50 which ?eld since these grids are connected to the high is sealed into the envelope 4. 48 is a control elec frequency circuit. The electrons are accelerated 25 trode which may be of any suitable form, such as or retarded depending upon the polarity of the an opening in the sealed-in ring 5|, as shown, or high frequency ?eld at the time of traversal so a grid-like structure supported by the ring 5|. that velocity variations then exist in the electron 4'! is a longitudinally accelerating electrode which stream. During traversal of the distance between may be of any suitable form, such as an opening grid 24 and the interaction space between elec 30 in the sealed-in ring 45, as shown, or a grid-like trodes 2 and 3, the electrons which have been structure supported by the ring 45. 42 is a, ra accelerated tend to overtake those which have dially accelerating anode which is connected to been retarded so that by the time the interaction and supported by the sealed-in ring 52. The space is reached the electrons of the stream are anode 42 also forms the continuation inside the ' in groups. In other words, the velocity variations 35 envelope 4 of the outer conductor 44 of the ex in the electron stream have been converted into ternal coaxial output circuit which is also con charge density variations, Each group of elec nected to the ring 52. 4| is a diverging rod, so trons enters the high frequency ?eld in the inter called because it is maintained at a lower poten action space in the proper phase to contribute tial than the anode and causes the electrons in energy to the ?eld and remains in that phase re 40 the stream to diverge radially toward the anode lation to the ?eld as it follows the helical path, 42. It is supported by and connected to the giving energy to the ?eld each turn of the helix sealed-in disc 53 which also forms the continua just as do the useful electrons following path I 3 tion inside the envelope of the inner conductor in Fig. 1. However, unlike the condition in Fig. 43 of the external output circuit which is also 1, the electrons are collected at collector 20 and it 45 connected to the ring 53. The sleeve 46 attached is not necessary to collect at electrodes 2 and 3 to the sealed-in ring supporting the electrode 41 energy-absorbing electrons such as follow the overlaps the end portion of member 42 and forms path I2 in Fig. 1. In the grouping process, per therewith a by-pass condenser intended to place formed by the phase lens 23, 24 in conjunction electrode 4'! and the end of member 42 at the with thedrift space following, electrons which 50 same high frequency potential and aid in prevent would otherwise reach the interaction space at ing radiation from the end of 42. The members periods of the cycle such as to absorb energy from 4| and 42 which constitute portions of the co the high frequency ?eld are moved in position axial output circuit are also the electrodes which along the path of the stream so as to be with the serve to produce the high frequency electric ?eld electrons reaching there at the proper periods to 65 in the interaction space between 4| and 42. The deliver energy to the ?eld. Thus, in eifect, most spaced sliders 54 and 55 with the capacitance be of the electrons in the stream are made useful, tween them close the coaxial resonant output cir energy-giving electrons and it is not necessary cuit for high frequencies at a suitable position to adjust critically so as to collect energy-absorb along conductors 43 and 44, insulation for biasing ing electrons early in the interaction space and 60 potentials being provided by the space separat depend upon such collection to provide the sort, ing action to give a preponderance of positive ing the sliders 54 and 55. The tube, especially the portion to the right of electrode 41, is subjected energy transfer from the electron stream to the to a uniform longitudinal magnetic ?eld of an high frequency circuit. Other means of pre intensity such that the precessional frequency of grouping to provide a preponderance of energy 65 the electrons equals the frequency of operation, giving electrons among those entering the inter action space will be described later. this magnetic ?eld being produced by the elec' . Advantages of the arrangement of Fig. 2, there fore, are that the cathode is removed from the Electrons emitted by the cathode I are ac celerated and the emission is controlled in in ?eld of interaction, thus avoiding electron bom bardment and other di?iculties of electronic con gestion and that more e?'icient operation is had on account of the transformation into energy tromagnet 5. tensity by the control electrode 48. Electrode 41 injects the electrons into the space between 4| and 42 in the output circuit at a longitudinal ve locity small compared to the radial velocity pro giving electrons of otherwise energy-absorbing duced by the anode 42. The radial accelerating electrons. 75 anode 42 is operated at a su?iciently high positive 2,409,229 ‘ ‘8 potential to establish the critical grazing condi tion for the electrons whereas the diverging rod 4| is operated at a very low potential in order to insure that the electron trajectories become helices parallel to the axis of the tube as soon as 5 possible. Electrons which enter the output cham ber, between rod 4| and anode 42, in such a. phase that their velocities have radial components in the direction of an induced electric ?eld inten induced except when an input ‘signal is applied. Furthermore, increased ‘ef?ciency may be ex pected with class B or 0 operation on account of sharper grouping or the electrons; In order to eliminate the input loading caused by the electrons in the input gap between the cathode I and the grid 48, the length of the gap and the biasing voltage should be made such that the electron transit time across the gap is a period sity will be accelerated and, consequently, will 10 within the range between the period of a whole number of cycles of the operating frequency and strike the outer anode 42 and be removed. 0n the the period of that number increased by ‘one-halt other hand, electrons entering the output cham cycle. . her in a phase such that their radial velocity is It is obvious that some of the output power directed oppositely to an induced ?eld intensity may be coupled back to the input circuit to pro will continue to transfer energy to the induced duce'self-excitation. To illustrate this, a coaxial ?eld until they are collected by the rod 4| or line comprising outer conductor ‘I I and inner con the sealed-in disc 53. In such a mode of opera ductor ‘I2 is shown coupling the input and output tion, the density variation grid 48'has the func circuits, the connections to these circuits being tion only of controlling the amplitude of oscilla tion statically or according to the modulating sig 20 the same as those of the two lines 58, 59 and 89, ‘I0 previously described. The outer conductor of nal represented as coming from the source 49. If the line has an insulating section 13 and is pro no longitudinal sorting occurs the maximum vided with ?anges on each side of the insulating e?iclency could become only 50 per cent since ring 13 ‘to provide a path for high frequencies half of the electrons are of unfavorable phase and are wasted. A load for the high frequency output 2:3 through the capacitance between the two ?anges while insulating from each other the direct cur such as indicated by the resistance 60 may be I rent biasing voltages on the coaxial members Bi coupled to‘ the coaxial output system as illus and 66. The amount of energy transferred is trated in Fig. 4 or in any other suitable manner. controlled‘ by adjustment of the degree of cou In Fig. 4 the central conductor 59 of the coaxial line 58, 59, connecting to the output load 60, pro- _ pling as was described in connection with the input and output lines 58, 59 and 69, '10 and the jects into the interconductor space between mem~ phase of the energy introduced into the input bers 43 and 44. 6| represents a longitudinal slot circuit is determined by the length of the con in member 44 whereby the projecting portion of necting line. ‘The phase may be made such as 59 may be positioned from the end of the coaxial to add to the input- energy and provide regenera output circuit closed by sliders 54 and 55 as de sired to adjust coupling impedances. tion or it may bereversed to stabilizerthe gain < Fig. 5 illustrates a tube and circuits very similar and reduce distortion. The regenerative action to those of Fig. 4 but arranged to function as a may be made such as to produce self-oscillation in which case the circuit becomes that of a high unilateral ampli?er. A tuned coaxial input cir cuit, similar to the output circuit of Fig. 4, com 40 vfrequency generator and the external input cir cuit of the ampli?er arrangement may be elimi prising outer conductor 66, the end closure made nated. High e?iciency operation may be obtained up of sliders 61 and 68 and inner conductor 65 is through the use of regeneration to enhance the connected between the control electrode 48 and electron grouping and so place as many as pos the cathode l by the sealed-in rings 50 and 5|. The control electrode 48 and its annular support 45 sible of the electrons into favorable phase posi tions before they enter the interaction space in ing ring 5| close and prevent radiation from the the output circuit. tube end of the coaxial circuit. This input circuit The tube and circuit of Fig. 5 may be modi?ed is energized by the high frequency to be ampli?ed so that the grouping of electrons into favorable which is represented in the ?gure as coming from source 14 and coupled through the coaxial line ~ 69, 10, the longitudinal slot 62 permitting the desired positioning of the projecting end of 10 along the coaxial input structure. Other features of the tube and circuit, with the exception of the feedback coaxial line ‘ll, 12 are thesame as in Fig. 4. phase positions before entering the output circuit is accomplished by the velocity variation control method somewhat as shown in Figs. 2 and 3. The modi?cation required for this is only in the input portion of the circuit and the essentials are'indi cated in Fig. 6 which is‘ a modi?cation of the por tion of Fig. 5 to the left of the line AA. The por tion to the right of the line AA, not repeated in Fig. 6 is the same as that to the right of line AA cathode I is density modulated by the high fre in Fig. 5. In other words, the tube and circuit quency input voltage impressed between the elec trode 48 and the cathode I. That is, the charge 60 to the right of the electrode 41 (or line AA) is the same for both Fig.6 and Fig. 5. The input por density of the electron stream is varied in accord tion of the tube is quite different because in the ance with the high frequency input voltage. velocity variation method of operation the elec Hence more electrons enter the output interaction trons must enter the input gap, or interaction space, to the right of electrode 41 and between members 4| and 42, in one phase than in‘ the 65 space, with a ?nite velocity and a drift space must be provided between the input and the output opposite resulting in a net induced high frequency interaction spaces or other grouping means must ?eld. When no input signal is applied, oscillation caused by plate or anode sorting of electrons, the _ be employed. In Fig. 6 the input gap, or inter action space, is between the electrodes 83 and 84 type of electron grouping utilized in the Fig. 4 arrangement, is prevented by operating the anode 70 which may be openings in the conducting annular rings 85 and 8B sealed into the tube envelope 4. 42 at a potential low enough to avoid the critical These electrodes are energized by the high fre grazing condition by a wide margin. Also, the quency energy to be ampli?ed which is for con electrode 48 may be biased negatively with respect venience indicated as coming from source 14 into to the cathode such that so-called class B or C operation is had and so insure that no output is 75 the resonant cavity bounded by the closure mem In operation, the electron stream from the _ 2,409,222 ‘ 10 9 her 80, the coaxial conductors 65 and 66, the rings ‘85 and 86, and the electrodes 83 and 84. A high frequency ?eld, therefore, exists between ode l and control electrode 48 but have sufficient capacitance between them to provide a low im pedance path for high frequency current, thus effectively closing the cavity at that point. The the electrodes 83 and 84 whenever the input cav ity is energized. Obviously, these grids may be energized to produce the high frequency ?eld be output resonant cavity is bounded by the con ducting member 91, the sealed-in rings 92 and 93 and the interleaved sets of segments 94 and 95. In the ?gure, 94 and 95 each have two diametri tween them in any suitable manner. Any type of resonant cavity, a coaxial system as illustrated, a lecher system or other means may be employed cally opposite segments. Obviously other num .for the purpose. 10 bers of segments'may be used. It will be seen A cathode I and a composite accelerating that the interleaved sets of segments 94 and 95 electrode 2|, 22 as described in connection with surround a tubular interaction space such as is ' Fig. 2 produce the stream of electrons which is . surrounded by the plates 2_ and 3 in Figs. 1, 2 projected across the input gap between electrodes and 3. They serve as electrodes to produce high 83 and 84, through the drift space between elec 15 frequency ?elds within the interaction space. A trodes 84 and 41 and thence into the output static magnetic ?eld with lines of force parallel interaction space between members 4| and 42. to the axis of the device is produced in the inter A typical path of a portion of the electron stream action space by the electromagnet 5 or other suit is indicated by the dotted line 88. After passing able means. The segments of 94 and 95 are the grid electrode 41, the electron stream is 20 maintained at a. potential positive with respect made divergent by the high positive potential of to the cathode by potential source 98, the collec anode 42 and the low potential on the diverging tor 96 is maintained at a lower potential positive rod 4|, and under the in?uence of the axial mag with respect to the cathode by means of poten— netic ?eld produced by the electromagnet 5 the tial source 99 and thecontrol electrode 48 may electrons are caused to follow helical paths such 25 be maintained at a potential either positive or ' that the precessional frequency is the same as the negative with respect‘ to the cathode by the tap frequency of operation. In a manner similar to connection to potential source 98. Electrons that explained in connection with the operation leaving the cathode I under the control .of elec of Fig. 2, the velocities of the electrons are varied ,trode 48 pass into the interaction space sur-, as the electron stream passes through the input 30 rounded by the segments of 94 and 95 under the gap between the electrodes 83 and 84 which con in?uence of the positive potential on those seg stitute what has been previously termed a phase ments. The electrons here encounter the static lens. The electrons are accelerated or retarded magnetic ?eld as well as the high frequency ?eld in passing from electrode 83 to electrode 84', de—' occasioned by .high frequency energy in the out pending upon the polarity of the high frequency put circuit. The electrons enter the interaction ?eld therebetween at the time of traversal. Then space with components of velocity in radial in passing throughthe drift space from electrode directions so that they are constrainedby the 84 to electrode 4‘! the faster, accelerated, elec staticv magnetic ?eld to follow helical paths trons tend to overtake the slower ones so that through the interaction space‘and thence to the the electrons become arranged into groups and 40 collector 96. ' ' ~ ' the electron stream becomes density modulated The inputcircuit is energized by high frequency in accordance with the high frequency input energy which may come from an external source before it enters the output interaction space be such ‘as is represented by source 14 which is tween members 4| and 42. Thus, just as in the ' coupled to the input circuit through the coaxial operation of the Fig. 5 arrangement, more elec 45 line 69, 10. The electron stream is density modu trons enter the output interaction space, beyond lated by the high frequency input voltage im electrode 41 and between members 4| and 42, in pressed between the control electrode 48 and the one phase than in the opposite, resulting in a cathode I, Thus the electrons enter the inter net induced high frequency ?eld. Also, when no input signal is applied, oscillation caused by plate sorting is prevented by operating the anode 42 at a potential low enough to avoid the critical grazing condition by a wide margin. The high frequency input source is coupled to the input action space in groups more or less distinctly sep arated, depending'upon the mode of operation as discussed in connection with the operation of Fig. 5. Since, due to the grouping, more electrons enter the interaction space in one phase of the resonant system the same as shown in Fig. 5 55 and the feedback coaxial line ll, 12 functions just as the similar line in Fig. 5. Fig. 7 illustrates an arrangement similar to ‘that of Fig. 5 in that it utilizes closed resonant cavity input and output circuits and space charge 60 control of the electron stream. It differs from Fig. 5 principally in that an interleaved four segment plate is used, no diverging rod such as 4| in Fig. 5 is employed and the electrons are collected by a collector in the end of the tube 65 opposite the cathode after having passed through the interaction space. The input resonant cavity is bounded by the conducting members 90 and 9|, and the sealed-in rings 50 and 5| with which are associated the 70 cathode l and space charge control electrode 48, respectively. The ?anges I00 and “II, which are parts of members 90 and 9|, respectively, are spaced from each other to insulate the direct current biasing potential applied between cath high frequency cycle than in the opposite phase, a net induced high frequency ?eld results and high frequency energy is delivered to the output circuit in accordance with the high frequency energy im pressed upon the input circuit. After the elec trons have passed through the interaction space interacting with the high frequency field at each turn of the helical path and at each space be tween the interleaved plates they are collected by the collector 96 whether they have given energy to or absorbed energy from the output circuit, the gain of energy by the output circuitdepend ing upon the preponderance of energy-giving elec trons which in turn is dependent upon the extent of electron grouping in the input circuit. Pre grouping of the electrons may be such that no electrons need strike the segments of 94 and 95 and all may be collected at low voltage by the collector 96. Since this collector may be made large and capable of dissipating a large amount of power the device is inherently capable of gen- 75 erating a correspondingly large amount of high 2,409,222 11 frequency power, thus overcoming aserious limi tation of conventional magnetron structures. An 12 ' general direction of which an electron stream is directed and along which within the tube are advantage of the four-segment plate, illustrated located in substantial axial alignment and axially in Fig. 7, is that a less intense magnetic ?eld is required than with a two-segment plate as illus trated in Figs. 1, 2 and 3. In connection with Fig. 1 it was stated that the product AH for that spaced one from another, a cathode, at least one electron control electrode, and a system of high frequency output electrodes arranged to impress a high frequency electric ?eld upon a space sym metrically surrounding a. portion of said axis, means including the said system of high fre For a four-segment plate AH need be only half that, or approximately 6,500. A larger number of 10 quency output electrodes for producing a high frequency electric ?eld in the said space sym segments may be used if desired. In general, for metrically surrounding the axis, means for main an n segment plate AH should approximate taining a static magnetic ?eld in at least a por 13,000 tion of the space occupied by the said high fre 21/2 15 quency electric ?eld such that the lines of force of the static magnetic ?eld are substantially Also the arrangement of Fig. '1 like that of Fig. 5 has the advantages of non-radiating input parallel to the said axis and perpendicular to the electric lines of force of the high frequency ?eld, and output circuits. Fig. '7 illustrates primarily an ampli?er ar means for projecting a stream of electrons into rangement with input and output circuits en the space occupied jointly by the two said ?elds with a component of direction perpendicular to tirely separated and, as such, shows a form of unilateral ampli?er of the magnetron type. 0b the lines of force of the static magnetic ?eld, and viously, the input and output coaxial lines, 69, ‘I0 means including the electron control electrode for varying the charge density of the electron and 58, 59, respectively, may be connected to gether through a suitable length of line for the stream at the said high frequency before its en purpose of producing self-oscillations so that the trance into the space occupied by the combined arrangement will function as an oscillation gen said ?elds. 3. A system according to claim 2 above char erator. Also, a feedback line may be added to interconnect the input and output cavities as il acterized in that the means for varying the lustrated in Fig. 5 for the purpose of providing 30 charge density of the electron stream comprises regeneration or to stabilize the gain and reduce electrodes associated with the electron path which may be connected to a high frequency electrical distortion. Various embodiments of the invention illus circuit to produce, when the circuit is energized, trating devices of the magnetron type utilizing a high frequency ?eld throughout a portion of ’ non-radiating circuits, means for e?iciently in 35 the electron path whereby electrons passing troducing and controlling the electron stream and therethrough are accelerated positively or nega means for modulating the electron stream at tively depending upon the phase of the ?eld en high frequency before it reaches the output por countered. tion of the circuit have been shown and the utility 4. In combination, an electrically resonant of such devices as unilateral ampli?ers as well 40 chamber with which when energized there is as as oscillators has been indicated. It is not in sociated a high frequency electromagnetic ?eld, tended that the scope of the. invention is limited 'means for maintaining superposed upon the high to these particular embodiments but only as de frequency ?eld a static magnetic ?eld of which ?ned by the appended claims. the lines of force are substantially perpendicular What is claimed is: 45 to the electric lines of force of the high frequency 1. A high frequency system comprising an elec ?eld, means including a cathode external to the tron tube having a longitudinal axis along the chamber for projecting a stream of electrons into general direction of which an electron stream is be space occupied by the combined said ?elds, directed and along which within the tube are ."id means for varying the charge density of the located in substantial axial alignment and axially 0 electron stream before it enters the said ?eld spaced one from another, a. cathode, at least One occupied space whereby it is enabled to deliver electron control electrode, and a system of high energy to the said high frequency ?eld at the frequency output electrodes which are portions frequency of the charge variation. of an electrically resonant chamber and are ar 5. A high frequency electronic device compris ranged to impress a high frequency electric ?eld ing an electrically resonant chamber capable of upon a space symmetrically surrounding a portion being energized to produce within itself a high of said axis, means including the said system of frequency electric ?eld, means for producing a high frequency output electrodes for producing static magnetic ?eld superposed upon at least a a high frequency electric ?eld in the said space portion of the said high frequency ?eld such that symmetrically surrounding the axis, means for the lines of force of the static magnetic ?eld are maintaining a static magnetic ?eld in at least a substantially perpendicular to the lines of force portion of the space occupied by the said high of the high frequency electric ?eld, and electron frequency electric ?eld such that the lines of discharge tube means including a cathode ex force of the static magnetic ?eld are substantially ternal to the resonant chamber for projecting parallel to the said axis and perpendicular to electrons into the space occupied by the said the electric lines of force of the high frequency superposed magnetic and electric ?elds, such that ?eld, means for projecting a stream of electrons the electrons have components of direction par into the space occupied jointly by the two said allel to the lines of force of the high frequency ?elds with a component of direction perpendicu electric ?eld, whereby high frequency energy is lar to the lines of force of the static magnetic generated within the chamber. ?eld, and means including the electron control 6. A high frequency electronic device compris electrode for varying the charge density of the ing an electrically resonant chamber capable of electron stream before its entrance into the space being energized to produce within itself a high occupied by the combined said ?elds. frequency electric ?eld, means for producing a 2. A high frequency system comprising an elec tron tube having a longitudinal axis along the 76, static magnetic ?eld superposed upon at least a two-segment structure should approximate 13,000. 2,409,222 ' ' l3 portion of the said high ‘frequency ?eld such that the lines of force of the static magnetic ?eld are traversing the said space becomes charge-density modulated at a frequency to which thehigh fre- , substantially perpendicular to the lines of force of the high frequency electric ?eld, and electron frequency is generated in the high frequency sys-. discharge tube means including a cathode exter tem. quency system is resonant whereby energy at that ‘ Y 7 nal to the resonant chamber for projecting elec 10. A high frequency electronic device,v com trons into the space occupied by the said super prising an electron discharge tube having an posed magnetic and electric ?elds, such that the evacuated envelope which includes at least a por electrons have components of direction parallel tion of a resonant coaxial high frequency system to the lines of force of the high frequency elec 10 capable of being energized to produce within it tric ?eld, whereby high frequency energy is gen self a radial high frequencyelectric ?eld,gmeans erated within the chamber, the said electron tube for maintaining an axial, static, magnetic ?eld means including means for varying the charge between the inner and outer conductors in a, por density of the stream of electrons before the elec ' tion of the high frequency system included in the trons enter the resonant chamber at a frequency 15 electron tube envelope, an electron emitting cath below that to which the chamber is resonant, ode, means for introducing electrons into the whereby the intensity of the generated high fre space between the inner and outer coaxial con quency energy is modulated in accordance with ductors of the high frequency system occupied the variations of the charge density of the stream by the said electric and magnetic ?elds such that of electrons. 20 the electrons have radial components of direction, '7. In combination, an electrically resonant and means for varying the charge density of the chamber capable of being energized to produce stream of electrons before it enters the said space within itself a high frequency electric ?eld, means for producing a static magnetic ?eld superposed upon at least a portion of the said high frequency ?eld, such that the lines of force of the static magnetic ?eld are substantially perpendicular to ‘the lines of force of the high frequency ?eld, at a high frequency whereby energy at that fre quency is generated in the high frequency sys tem. . 11. A high frequency electronic device, com prising an electron discharge tube having an evacuated envelope including at least a portion electron tube means including a cathode external of a resonant coaxial high frequency system ca to the resonant chamber for projecting a stream 30 pable of being energized to produce within itself of electrons into the space occupied ‘by the said a radial high frequency electric ?eld, means for superposed magnetic and electric ?elds, such that maintaining an axial, static, magnetic ?eld be the electrons have components of direction per tween the inner and outer conductors in a portion pendicular to the lines of force of the static mag of the high frequency system included in the elec netic ?eld, the said electron tube means includ- . ing means for modulating the electron stream prior to its entrance into the said space occupied by the superposed magnetic and electric ?elds, at frequencies within the range to which the said tron tube envelope, an electron emitting cathode, means, including electric potential means, for in troducing electrons into the space between the coaxial conductors of the high frequency system occupied by the said electric and magnetic ?elds I resonant chamber is resonant whereby energy at 40 such that the electrons have radial components frequencies corresponding to the modulating fre of direction, means for varying the charge density quency is generated within the chamber. of the stream of electrons before it enters the said space at a- high frequency whereby energy at that frequency is generated in the high frequency system, the electric potential means and the in tensity of the static magnetic ?eld being so ad justed that no high frequency energy is generated in the high frequency system when the said means for varying the charge density of the stream of electrons is inactive. 12. A device according to claim 11 wherein the means for varying the charge density of the stream of electrons comprises means for varying 8. A high frequency electronic device, compris ing an electron discharge tube with an evacuated envelope which includes at least a portion of a resonant coaxial high frequency system capable of being energized to produce within itself a radial high frequency electric ?eld, means for maintaining an axial, static. magnetic ?eld be tween the inner and outer conductors in a por tion of the high frequency system included in the electron tube envelope, an electron emitting cath ode. and means for introducing electrons into the space between the inner and outer coaxial con the space charge of the stream of electrons. ' ductors of the high frequency system such that ., 13. A device according to claim 11 wherein the the electrons have radial components of direction. means for varying the charge density of the 9. A high frequency electronic device, compris stream of electrons comprises means for varying ing an electron discharge tube having an evacu the velocities of the electrons. ated envelope which includes at least a portion of 14. An electronic device comprising, hollow a resonant coaxial high frequency system capable of being energized to produce between its inner and outer conductors a radial high frequency (it) electrically resonant input and output systems which are closed to substantially con?ne high fre quency electromagnetic ?elds within, means for electric ?eld, means for maintaining an axial, energizing the input system to produce a desired static, magnetic ?eld between the said inner and high frequency ?eld therein, means for maintain outer conductors in a portion of the high fre 65 ing a static magnetic ?eld having lines of force quency system included in the electron tube en superposed upon and substantially perpendicular velope, an electron emitting cathode, and means, to lines of force of the high frequency electric including electric potential means, for intro ?eld associated with the output system when it is ducing electrons into the space between the inner energized, electron tube means for projecting a and outer conductors of the high frequency sys 70 stream of electrons, ?rst, through the high’fre tem occupied by the said electric and magnetic quency ?eld of the input system whereby the ?elds such that the electrons have radial com charge density of the electron stream is varied ponents of direction, the electric potential means in accordance with the high frequency energy in and the intensity of the static magnetic ?eld be the input system, and subsequently, through at ing so adjusted that the stream of electrons 75 least a portion of the high frequency ?eld of the 2,409,222 15 output system upon which the static magnetic ?eld is superposed with components of direction perpendicular to the lines of force of the super posed static magnetic ?eld whereby energy in ac cordance with the charge density variations of the electron stream is generated in the output system. 16 the input coaxial system within the tube envelope and spaced from the foraminate member closing the end of the outer conductor of the coaxial input systemv such that when the input system is energized a high frequency control voltage is impressed between the foraminate member clos-‘ ing the input system and the cathode, electric potential means for maintaining the outer con 15. A device according to claim 14 character ductor of the coaxial output system and its clos ized in that the electron transit time through the high frequency ?eld of the input system is a pe 10 ing foraminate member at positive potentials with respect to the cathode, and electrical potential riod between the period of a whole number of means for maintaining the inner conductor of cycles of the high frequency ?eld and the period the output coaxial system at a potential lower of that number increased by one-half cycle. than that of the outer conductor whereby elec 16. A device according to claim 14 and includ ing a feedback connection whereby high fre 15 trons are drawn from the cathode through the foraminate members into the interconductor V quency energy may be transferred from the out space occupied by the said superposed static mag put system to the input system. netic and high frequency electric ?elds with radial 17. A high frequency electronic device compris components of velocity, and means for energizing ing an electron tube having an evacuated en velope, a resonant coaxial output system, one end 20 the input coaxial system at a desired frequency‘ of operation to modulate the electron stream be of which is enclosed within the envelope of the fore it enters the output system whereby energy electron tube, a closure member substantially at the input energizing frequency is generated closing for high frequencies the end of the outer in the output system. coaxial conductor of the output system within 19. A high frequency system comprising an the electron tube, the closure member, however, 25 electrically resonant cavity generally toroidal in being foraminate to permit the passage of elec shape, the boundary of which is a shell of con trons therethrough, means for maintaining an ducting material consisting essentially of two con axial static magnetic ?eld between the inner and centric tubular portions one within the other and outer conductors in a portion of the output sys tem included within the tube envelope, the static 30 two annular portions connecting the two tubular magnetic ?eld being superposed upon the radial portions to each other at their ends, thereby enclosing a space extending radially between the high frequency electric ?eld produced in the in two tubular portions and longitudinally between terconductor space when the output system is the two annular portions, the inner tubular por energized, means including electrical potential means connected to the coaxial conductors of the 35 tion of the shell having a slit through its con ducting material, the slit extending alternately output system for projecting a stream of electrons in longitudinal and circumferential directions di~ through the said foraminate closure member into viding the inner tubular portion into two parts, the space between the said coaxial conductors each part comprising a plurality of segments in such that the electrons have components of direc terleaved with segments of the other part such tion radial with respect to the coaxial conductors. that the inner tubular portion comprises a plu 18. A high frequency device comprising an elec rality of longitudinal segments with alternate segw tron tube having an evacuated envelope which encloses as electrodes the end portions of resonant ments connected together and to the other mate rial of the conducting shell at opposite ends of coaxial input and output systems which are res onant at substantially the same frequency and 45 the inner tubular portion, those connected at one end being separated from those connected at the are axially aligned with the ends Within the tube other end by the said alternately longitudinal and envelope facing and spaced from each other, the circumferential slit, means for maintaining a lon outer conductors at these facing ends being sub gitudinal static magnetic ?eld within the said stantially closed for high frequencies by conduct ing members which are foraminate to permit the 50 inner tubular portion, means for projecting a passage of electrons therethrough, means for stream of electrons into the inner tubular por tion with components of direction perpendicular maintaining an axial static magnetic field be to the lines of force of the static magnetic ?eld. tween the inner and outer conductors in a portion and means for varying the charge density of the of the output system included within the tube envelope, the static magnetic ?eld being super 55 electron stream at the resonant frequency of the cavity whereby high frequency energy is trans posed upon the radial high frequency electrie ?eld produced in the interconductor space when the ferred from the electron stream to the cavity. output system is energized, an electron emitting cathode connected to the central conductor of JACK A. MORTON.