Патент USA US2136105код для вставки
NOV.8, 1938. GJOBST > I 2,136,105 ELECTRON DISCHARGE DEVICE Filed Sept. 3, 1956 TIME _ V n’ K I] 341411 ANODE l POTf/VIML _ L ' 12:9. 6‘ A ' ' - ‘?/= / =' =1 _ '4 x52; PUTENT/AL _ I ' ? , '= _ Y INVENTOR QUNTHER JOBS!‘ '0 ‘ . ' » I ‘i _ ' . RNEY ' Patented Nov. 8, 1938 UNITED STATES aren't 2,136,105 ELECTRON DISCHARGE DEVICE Giinther J obst, Berlin, Germany, assignor to Telefunken Gesellschaft fiir Drahtlcse Tele graphic in. b. 11., Berlin, Germany, a corpora tion of Germany Application September 3, 1936, Serial No. 99,231 In Germany September 18, 1935 1 Claim. (C1. 250—-27.5) My invention relates to electron discharge de—' vices intended for the production of oscilla tions and more particularly to improvements in devices of the negative resistance type in which 5 with high anode potentials less current is taken by the anode than with smaller anode potentials. The principal object of my invention is to pro pressed, or on secondary electrons, ions or space charge effects, or in the Barkhausen-Kura case on a sorting out of the elects‘ in the present case the variable penetrability of the anode with respect to the electrons as a function of the anode potential or electron speed is the means relied upon for ful?lling the above condition. vide an electron discharge device which can be used for ampli?cation, recti?cation, mixing dif There is produced by the thus presupposed variable penetrability l0' ferent frequencies or for producing oscillations, and particularly to provide an improved type of properties of the anode a , ll) relationship between anode current and anode potential in which there is ?rst an increase of such device ‘having a negative resistance char the internal resistance of the discharge plane with increased penetrability and with further in acteristic. crease of penetrability of the anode as a function 15 . ‘ The novel features which I believe to be char15 acteristic of my invention are set forth with par ticularity in the ‘appended claims, but the in— vention itself will best be understood by refer ence to the following description taken in con nection with the accompanying drawing in which Figure 1 is a diagrammatic representation of an 20 electron discharge device. embodying my inven tion, and a circuit therefor; Figure 2 is a graph ical representation of the operation of the de vice shown in Figure 1 under different conditions of anode voltage; Figure 3 shows a circuit ar 25 rangement embodying my invention; Figure 4 is a graphical representation of anode voltage con— ditions during operation of the circuit embodying my invention and shown in Figure 5; Figure 5 shows another ‘circuit arrangement embodying 30 ‘my invention; and Figure 6 is a diagrammatic representation of a modi?cation of an electron discharge device embodying my invention. By extending the ?eld of application of the arrangement to very short waves where the 35 transit time of the electrons is of importance with 40 respect to the length of the period of the ac tion, the more general formulation of above con ditions applies namely that on the electrons that are taken up- by anode the work (t) efKALVA be ds is done which is smaller than CVAO (where e sig 45 ni?es the elementary quantum, Vac the anode ’ direct potential, @V_,<o__ O as _E8t 50 the ?eld intensity as a function of time, or the potential gradient, and dc the path element). While generally the means for the generation of oscillations is dependent either on the use of grids, positioned ahead of anode and properly ~55 controlled, which ful?lls the condition above ex of a rising anode potential, a reversal of the sign of this resistance or a decrease. The latter ac tion takes place when the internal resistance is already high due to additional means such as a screen grid between the cathode and anode or when working on the saturation point of the "20 cathode ?lament. In case the resistance of the cathode-anode discharge path is already statical ly or dynamically negative due to some cause or other, for example controlling the grid in suitable phase, the means provided for the 25 penetrability variation as a function of anode potential can be considered as adding these properties and result for instance in a reduc tion of the absolute value of the negative resist 30 ance or in an improvement of the ef?ciency. It has been known since the experiments of Lenard that thin foils of a metal with small atomic weight for electrodes are the more per meable the higher the electron speed. In this manner the prior art was successful in having 35 electrons with high potential leave the vessel through metallic foils that formed the closure of a vacuum vessel against air. The so-called Lenard windows nevertheless have still consider able thickness in order to be able to withstand 40 the difference in air pressure between vacuum and atmosphere so that they have a proper permeability only for electrons of very high speed. If however, as can be done with the means available at the present state of the art, optically transparent foils are used as anodes inside the‘ tube, eliminating a mechanical stress in above sense, the penetration of the anode is achieved at relatively small anode potentials or electron speeds. (See for instance German pat tent 587,113, which likewise proposes the use of such a thin metallic foil, however for‘ the entirely different purpose of releasing secondary elec— trons by the penetrating primary electrons.) During the passage through the anode the elec 45 2 2,136,105 trons are subjected to an average velocity loss which results in a heating of the anode, and with smaller anode potentials or lesser electron speeds the passage of the electrons through the anode is prevented. The greater the anode po tential or speed of the electrons the greater the probability of the electrons passing through the anode and the smaller therefore the anode cur 10 rent. The electrons passing through the anode are caught by an electrode disposed behind the anode: or the electrons may be re?ected in the case of very short waves. In the ?rst case this electrode may be a solid sheet or dense net and is 15 impressed with a slightly positive potential, in the case of short waves it may have a negative potential. In accordance with my invention I reproduce the atomic ?eld conditions existing in the interior 20 of metal foil electrodes by means of an arrange ment of coarser type. Just as within the atoms the electron paths are more curved and ?nally are bound in the atomic bond, the smaller the speed of the shot-through electron, in the same way the electron paths are curved by means of the arrangement shown diagrammatically in Fig ure 1 in which the anode A consists of a pair of interposed electrodes for instance one of bars ill and the other of plates or slats II in alternating 30 succession. Between these electrodes there is ap plied a constant potential difference and the higher potential is applied to the larger electrode or to the electrode comprising the plates. With higher anode potentials and hence greater elec 35 tron speeds in the neighborhood of the anode the electrons are de?ected relatively only a little by this potential difference and ?y through the anode. For the case where the anode potential or electron speed in the vicinity of anode is small, the electrons are de?ected much more 40 strongly and so that most of the electrons move toward the more positive part of the anode. An electrode S positioned between the cathode K and the anode A is positively biased with respect to the cathode for accelerating the electrons from the cathode to the anode. In Figure 2a the path of the electrons from the cathode K through the anode A to the plate P is designated by the lines provided with the arrow heads. It will be observed that under these con ditions of high plate voltage that the electrons pass through the anode without being de?ected to any considerable extent. In the case shown in 2b with the lower anode voltage applied, the elec 55 trons are de?ected from their path and are caught and retained principally by the plate portions of the anode electrode. In the circuit shown in Figure 3 an oscillating circuit comprising an inductance l2 and capacity 60 I 3 is connected between the cathode K and the anode A. The ?xed potential di?erence between the two electrodes forming the anode may be established by a resistance and condenser combi nation M or by a suitable source of voltage in the form of a battery. 65 A type of feedback arrangement for producing oscillations is shown in the circuit in Figure 5. The plate electrode portion of the anode is con nected to an intermediate point on the inductance 15 which is bridged by a capacity I6 to provide a tuned circuit. A battery I‘! is connected between the tuned circuit and the rod electrode portion of the anode so that the rod portion is at a lower potential. The voltage relationship on the rod portion of the anode and the plate portion of the 75 anode is shown in Figure 4, which represents the voltage relationship with respect to time dur ing operation of the tube. The lower ?xed poten tial E1 represented by the lower horizontal line is that applied to the rod electrode portion of the anode, the AC potential existing on this portion of the electrode being represented by the curve whose axis is the ?xed potential E1 applied to this electrode. The higher positive potential E2 is applied to the plate electrode portion of the anode and the superimposed AC potential is shown as the curve whose axis is the horizontal line repre senting E2. While a battery i1 is shown in Figure 5, it is of course possible to substitute a resistor and condenser combination such as shown in [4 of Figure 3. While in the arrangements above the more or less large penetrability of the anode is the result of the ?eld relations inside the anode proper. I may use an arrangement where the combination of elements produces electron shadows and hence 20 electron beams, for instance diaphragms used in cooperation with geometrically adapted construc tions of the anode to furnish the desired effect. It is for instance a well known fact that in larger tubes the grid struts and wires form electron ‘ shadows on the anode whereby it may be directly observed that the points of anode impinged upon glow, while the ones not or less impinged upon appear dark. According to the potential im pressed on the grid causing the shadow and on 30 the anode, these light and shadow points have different locations on the anode. By perforating or cutting out those portions of the anode which are primarily impinged upon with higher poten tials I can produce the desired result. Factors to 35 be considered for the geometric development of the tube depend upon whether the electron dis tribution on the anode is produced by a shadow throwing electrode of ?xed potential or of alter nating potential coupled with the anode potential. Particularly in the latter case the optimum perfo ration or cutting out with respect to e?iciency may be made only for de?nite operating condi tions with respect to the amplitudes of anode and grid alternating potentials as well as the direct potentials. The experimental basis for the plac 45 ing of these perforations is obtained for example with the aid of a model tube of the type here in question which may be photographed for the momentary values of the potential combination. From these pictures are obtained the points to be 50 perforated or cut out for a certain purpose of ap plication. It may be pointed out that the perfo rations must not be-of such size that thereby considerable ?eld variations, as compared to the 55 ?eld of the non-perforated or cut out anode, may occur at remoter distances from the cathode. The purpose in view would thus not be gained for the electron path would be de?ected too early in the direction of the solid parts of anode. 60 A further embodiment of my invention is shown in Figure 6. The electrons pass through a dia phragm S having an aperture and to which is ap plied a positive potential with a certain velocity given by this potential and are deflected by the 65 ?eld of the anode disposed parallel to the path of the electrons passing through the diaphragm. If the anode potential is large, the de?ection is greater, and the electrons ?y through the perfo rated part A’ in the vicinity of the slot and land 70 on the pick-up surface P located in the rear thereof. With smaller anode potentials the de ?ection of the electrons by the transverse ?eld is less and the electrons land accordingly on the non-perforated parts of the anode A. 76 3 2,136,105 will be apparent that my invention is by no means It may be added that the pick-up electrode last referred to may also be impressed with an alter limited to the exact forms illustrated or the use nating potential of su'table phase‘ It is thus for instance possible to modify the circuits in Figures indicated, but that many variations may be made in the particular structure used and the purpose for which it is employed without departing from 3, 5 and 6 in such a manner that the pick-up the scope of my invention as set forth in the electrode is impressed with a potential having a appended claim. phase rotation of 180° with respect to the anode potential. But is must not in turn in?uence the control in the vicinity and inside the anode. This and the passage of secondary electrons from the one to the other electrode may be prevented by a grid of suitable permeability and impressed with ?xed potential and positioned as a screen between P and A’. While I have indicated the preferred embodi ments of my invention of which I am now aware and have also indicated only one speci?c applica tion for which my invention may be employed, it What I claim as new is: An electron discharge device having a cathode and an anode permeable to electrons, said anode 10 comprising a pair of interposed electrodes of dif ferent size elements electrically insulated from each other and a second electrode adjacent the anode for receiving the electrons which pass through said anode, and a grid disposed between 15 the cathode and the anode. GiiN'rHER JOBST.