US2391016A - High-frequency tube structure - Google Patents

Description

HIGH FREQUENCY TUBE STRUCTURE Filed Oct. 31, 1941 s Sheets-Sheet 1 INVENTORS EDWARD L.GINZTO N WILLIAM W- HANSEN Dec. 18, 1945. En mz'roN ErALv 7 2,391,016

- HIGH-FREQUENCY TUBE STRUCTURE Filed Oct. 51, 1941 3 sheets-Sheet 2 iNVENTORS EDWARD L.G\NZTON WILLIAM W. HANSEN ATTORNEY 1945- E. L. GINZTON EFAL 7 2,391,016

HIGH FREQUENCY TUBE STRUCTURE I Filed Oct. 31, 1941 3 Sheets-Sheet INVENTORS EDWARD L.GINZTON WILLIAM W- HANSEN Patented fies. 18, 1945 STATES PATENT OFFIQE HIGH-FREQUENCY TUBE STRUCTURE Edward L. Ginzton, Rockville Centre, and William W. Hansen, Garden City, N. Y., asslgnors to Sperry Gyroscope Company, Inc., Brooklyn, N. Y., a corporation of New York Application October 31, 1941, Serial No. 417,228

3 Claims.

This invention relates, generally, to high frequency tube structure having directly attached hollow resonators of the type disclosed in Patout No. 2,242,275, filed October 11, 1937, by Russell H. Varlan, and copending applications Serial mentioned patents and application, wherein the evacuated portion of the tube structure is substantially confined to the electron beam path and the resonators are made external to the tube and adapted to be removable.

Another object of the invention is to provide removable resonators for use with such tubes, said resonators being external to the vacuum chamber of the tube, thus providing a high fre-" quency tube structure with a minimum amount of metal exposed to the vacuum itself, and so increasing the life of the vacuum by removing sources of gas.

mother object of the present invention is to provide a series of resonators which may replace any such externally attached removable resonator, thus increasing the frequency range over which such a resonator may operate very greatly beyond that provided by the tuning devices usually used with such resonators.

Still another object of this invention is to provide means of coupling such resonators electrisally by capacitative means to the grids contained inside of the vacuum envelope used with such high frequency tubes, thereby linking the alterhating electric field formed in the resonators to the grids.

it further object of the invention is to provide a resonator, one element of which is removable and replaceable by an element of different size.

miother object of the invention is to provide a resonator with one removable element so designed that tuning devices and coaxial energy removing or introducing lines may remain attached to the non-removab1e element, so that coaxial lines, and tuning devices do not have to be applied to each resonator, thus reducing the number of such devices required for a set of frequency ranges.

Other objects and advantages will become apparent from the specification, taken in connection with the accompanying drawings wherein the invention is embodied in concrete form.

In the drawings,

Fig. 1 is a. plan view, partly insection, of one embodiment of our invention.

Fig. 2 is a cross-section view of an alternate form of our invention.

Fig. 3 is a cross-section view of a modification of Fig. 2.

Fig. 4 is a cross-section view of another modification of our invention.

Fig. 5 is an enlarged cross-section view of a v fragment of Fig. 4.

Fig. 6 is an end view of the tube structures shown in Figs. 3 and 4.

Fig. 7 is a sectional view of a modified structure.

Similar characters of reference are used in all of the above figures to indicate corresponding parts.

Referring now to Fig. 1, onev form of our present invention is shown comprising resonators l and 2 adaptable to be slid directly over a vacuum envelope chamber 3 containing no internal grid structures, the resonator shape and the resuiting structure being similar to that of the high frequency tube disclosed-in the aforemen tioned Patent No. 2,242,275. Resonators shown permanently attached, but outside of their associated vacuum envelope, have been disclosed-in Patent No. 2,280,824, filed by Russell H. Varian and William W. Hansen, one of the present inventors. It is understood-that our invention is adaptable to any related type of tube structure using directly attached hollow resonant members,

singly or in'plurality, Fig. 1 being shown with two resonators merely by way of illustration. The toroidal hollow resonant members I and 2 are removably fitted upon vacuum envelope 3, 7

said vacuum envelope containing a focussing cathode structure 4 and a collector plate 80, as in previous disclosures. High frequency alternating voltages are built up on condenser members 6,

l and 8, 9 attached directly to theresonators I and 2, respectively, as described in prior art. The vacuum chamber 3 is preferably made of a relatively low-loss dielectric material, such as of certain glasses or silica, so that the electrical lines of flux adjacent to the condenserportions 6, I and 8, 9 inside the vacuum chamber do not tend to concentrate on the chamber walls. A good portion of the high frequency alternating voltage between condenser portions 5, l, is thus available for active use inside the envelope 3 for velocity modulation of the beam emitted from cathode 4 in the region l between the condenser elements 6, 1. Similarly, the effect of the bunches of the modulated beam, in region between the condenser elements 8, 9, is suitable to release a good portion of the energy available in these electron bunches for exciting oscillations in the toroidal resonator 2, in a. manner described in Patent No.

As disclosed in prior art, for a given cathode beam acceleration voltage, as supplied by a battery l2, it is desirable that cathode 4 and resonators and 2 beara fixed distance relation. Resonators I and 2 are shown spaced by clamp members I3, I 4 having holes suitably spaced to slide over concentric line members or posts |5, I6, and I1, I8, respectively, clamp members l3 and I4 being positioned by a base IS. The cathode spacmetal, is mounted coaxially inside of vacuum envelope 3 and grounded to resonator I as at 8|, providing an electric field free space between the resonators I and 2 in which the electron bunches form.

It is obvious from the aforementioned disclosures, that many varied types of tuning of the resonant cavities and 2 may be used to operate the resulting tube structure over a frequency range characteristic of particular resonatortuner combination. The tuning device shown in application Serial No. 342,912, filed June 28, 1940, by William T. Cooke, Joe J. Caldwell and David G. Clifford, or other tuning devices as later discussed, may be so adapted. It is also evident that, in the case of the structure shown in Fig. 1, one may supply a set of pairs. of interchangeable resonators of increasing frequency range, each range overlapping slightly the range of the previous pair of resonators, each pair of resonators being adapted to replace the resonator shown by sliding on and off the tube 3. the frequency range of a klystron-like high frequency tube may be greatly increased, this being a feature also of modifications of our invention to be further described.

Fig. 2 shows an alternate construction for our removable resonator as applied to a resonator shape disclosed in copending application Serial No. 343,528, filed July 2, 1940, by William W. Hansen, Russell H. Varian and Sigurd F. Varian, now Patent No. 2,311,658, granted February 22, 1943. Mutually spaced conducting tubes 24 and 25 fit closely in the inner diameter of a vacuum envelope 3 and serve to concentrate a highfrequency alternating electric field therebetween within the envelope. The tube 24 is held at .a desired positive potential with respect to the cathode (not shown) and is'also held in proper axial position by a conducting wire or wires 28 which may extend to the desired potential source; and, likewise, the tube 25 is similarly connected by wire or wires 29 leading to the metal drift tube In such manner,

, the screw 31.

30 also connected to a source that is positive with respect to the cathode, in order to prevent the electron beam from building up charges on said conducting tubes. The resonator 2| is provided at its condenser portion with walled sleeves 26 and 21 which fit over the external diameter.

of the vacuum envelope 3, which extend in the same sense and are positioned opposite and which are the sa'me length as sleeves 24 and 25, respectively. The concentric sleeves 24, 23 and 25, 21, form the plates of condensers, the dielectric 01' which is the material of the vacuum envelope 3.

. of resonator 2| will be practically all transferred to the sleeve members 24 and 25 by extending the length of the sleeve members.

Tuning of the resonator 2| may be accomplished by means of the rotatable paddle 33 in conjunction with the knob 32. The action of paddle 33, as explained in above mentioned Patent No. 2,280,824, depends upon the fact that it distorts the oscillating field in resonator 2| to a greater or less degree depending upon the relative orientation of the paddle. The resonator might also be tuned by replacing the rigid wall 3| by a flexible one and adapting the tuning mechanism of the aforementioned application Serial No. 342,912 to change the distance between the capacitive portionsof the resonator 2|, or by other means such as discussed in connection with Fig. 7. Concentric line 34, or a plurality of such concentric lines, may be provided for,

removal of energy from or introduction of energ into the resonator 2|.

In place of providing resonators which are slidably removable from the vacuum envelope, a construction such as shown in Fig. 3 may be used.

' Resonator 2| may be divided into halves as shown at 35 and 36 in Fig. 6, being hinged at 38 and clamped together by screw 31,- or may be divided into any convenient size and number of portions. Grid structures 22 and 23 are placed in male V-edged conducting disks 39 and 43 which are oriented coaxially to and are sealed to and form partitions in the. vacuum envelope 3, the V-edges of the disks projecting out of the wall of the vacuum envelope. The structure of Fig. 2 may also employ grids attached to sleeves 24 and 25, if desired. The halves of the resonator 2| have their condenser portions slotted with female V-edges of a diameter exactly matching the V edges of thedisks, as at 4|, 42. One wall 43 of the resonator 2| is made thin and flexible, so that no lateral or other strains are exerted on the glass to metal seals 44. The hinged halves 35, 36 of, resonator 2| are then folded around the disks 39, 40 and are clamped in position by Tuning of the resonator 2| may be effected by any of the methods preferably not requiring distortion of the resonator walls; i. e., by a tuner such as the paddle 330i Fig. 2. This form of our invention affords direct metallic contact for the high frequency current carrying surfaces, and so introduces no losses of energy such as dielectric loss.

The features of our invention can also be applied to modifications of klystron-like tubes as illustrated in Fig. 4, which shows a. variation of the structure shown in Fig. 3 of copending application Serial No. 268,898, filed April 20, 1939 by William W, Hansen, Russell H. Varian and John R. Woodyard, now Patent No. 2,259,690, granted October 21, 1941, wherein velocity grouping tubes of single resonant circuit type are disclosed. In such a tube, a hollow external cylindrical case 45 is arranged to contain an oscillating high frequency electric field, and to also contain, placed coaxially to member 45, a second smaller hollow cylinder 48. As described in the aforementioned application Serial No. 268,898, members 45 and 48 have aligned grid structures 41, 48, 48, and 58, through which an electron beam from focusing cathode 4 may be projected. Cylindrical memhere 45 and 46 are so laterally spaced that grids 41, 48 are closer together than grids 48, 58, affording a relatively low intensity high frequency field between the buncher grids 41, 48, wherein the electron beam is velocity grouped, and a relatively high intensity alternating field between the catcher grids 48,58, wherein energy absorption is effected, the electric fleld being substantially zero in the region in which supporting struts 8| and 6| are placed.

As shown in Fig. 6, the resonator 45 may be split in halves, hinged, and clamped around the vacuum envelope 3. The grids 41, 48, 48, 50 are mounted in alignment in conducting disks 52, 53, 54, respectively, and are sealed in envelope 3. These disks are supported in the envelope 3 in an exactly similar manner as the disks 38, 40 of the structure shown in Fig. 3. The disks periphcries, in place of being V-shaped, have a novel fitting which efiects removal of lateral and other strain from th glass to metal seals of the tube. The joints between the disks and the resonator walls are substantially as shown in Fig. 5. Here portion 54 of one of the disks is shown to have a peripheral flange 86 extending past the body of the disk. Likewise, the walls 55, 56, 51, 58 of cylindrical members 45 and 48, as shown by wall portion 58, have an inwardly extending flange 84. The sum of the widths of flanges 84 and 88 is made somewhat less than the total width of the disk, the disk portion 54 and th wall portion 58 being shown as having equal widths.

- Resonator 45 may be held in proper lateral position with'reference to vacuum envelope 3 by means of clamping devices such as shown in Fig. 1, or by other appropriate means. Then by means of the structure shown in Fig. 5, any strains due to inaccuracy of construction of the resonator 45 or of positioning of the disks 5|, 52,

53, 54 in the glass to metal sealing process, or any strains due to relative thermal expansions are not transmitted to the metal to glass seals.

The tube is shown provided with a focusing cathode 4 and focusing coil 60 energized by battery 82 through leads in hollow strut 8|, although such focusing may not necessarily be a feature of our invention.

Fig. 7 illustrates a structure that is quite similar to that shown-in Fig. 2 wherein a resonator 88 is slidable on or off the evacuated electron beam confining tube 89. Within the tube 88 there is provided the emitting cathode 80 that is maintained at a direct current potential diflerence with respect to an accelerating grid member 8| as by means of a battery I08. The grid member 8| underlies one wall of the resonator 88 and is capacity coupled thereto by the tube projecmembers and defining therewith a toroidal cavity tions 82 and 88 formed on the grid structure 9| and resonator 88, respectively. A second grid structure 84 is also contained within tube 88 in opposed cooperative relation with grid structure 8|. Grid structure 84 also has a tube projection 85 capacity coupled to a tube projection 88 also formed on the resonator 88. Thus, in use the standing electromagnetic field within resonator 88 establishes an alternating electric component between grid structures 8| and 84. This tube is shown as of the reflex type and has a reflector plate 81 held near cathode potential for refiect- As many changes could be made in the above I construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 7

Having described our invention, what we claim and desire to secure by Letters Patent is:

1. High frequency electron discharge apparatus, comprising a tubular insulating envelope, a pair of tubular members coaxially mounted within said envelope, an electron-permeable grid supported in each of the adjacent ends of said members providing a. narrow gap therebetween, a cathode adjacent one of said grids, a reflector electrode adjacent the other of said grids, a pair of conductive members substantially coplanar respectively with said grids and surrounding said envelope,v conductive means connected to said resonator. and a pair of tubular elements connected respectively to said coplanar members at the inner edges thereof and extending outwardly from said resonator and concentrically with respect to said first tubular members defining a capacitance between each of said last tubular elements and its corresponding tubular member.

2. High frequency electron discharge apparatus comprising a tubular insulating evacuated envelope, a pair. of tubular members coaxially mounted within said envelope and having adjacent ends, a grid'mounted in each of said ends and forming a narrow gap therebetween, a cathode adjacent one of said grids, a reflector electrode adjacent the other of said grids, means defining a cavity resonator removably surrounding said envelope adjacent said grids, and a pair of tubular elements connected at the inner edges V EDWARD L. Gmz'roN. wniLmM w. rmmsrm.

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