US2509325A

US2509325A - Electron discharge device for highfrequency

Info

Publication number: US2509325A
Application number: US695886A
Authority: US
Inventors: Warren Geoffrey William
Original assignee: MO Valve Co Ltd
Current assignee: MO Valve Co Ltd
Priority date: 1940-11-14
Filing date: 1946-09-10
Publication date: 1950-05-30
Anticipated expiration: 1967-05-30

Description

May 30, 1950 G. w. WARREN ELECTRON DISCHARGE DEVICE FOR HIGH-FREQUENCY Filed Sept. 10, 1946 INVENTOR Patented May 30,1950

UNITED ATS ' T OFFICE ELECTRON DISCHARGE DEVICE FOR HIGH- FREQUENCY Application September 10, 1946, Serial No; 695386 In Great Britain November 14', E940 Mimi fi i 0,.Au' us s, 1546 Patent expires November 14, 19

8 Claims. I

This invention relates to grid-controlled thermionic discharge devices of the type adapted to operate at frequencies as great as and even greater than 1000 mega cycles and to their manufacture. Such devices" have to have very small electrodes, accurately located with very small clearances between them, and yet the space occupied by the field between the electrodes must contain as little solid insulation as possible. The object of the invention is to provide a form for the electrodes and a method of assembling them that permits these antagonistic requirements to be realized in a very hi h degree.

According to the invention the manufacture of a device of the type specified comprises the following steps in the following'order: (1) Aifix-' ing the control-grid structuretoa support rigidly connected to a part of the envelope; (2) adjusting the anode so that it is properly located relatively to the grid; andafixihg it to a second support connected rigidly to a part of the envelope; (3) aihxing to the anode an insulating member carrying the cathode. The two said supports must be independent where the grid structure and anode are afiixed to them, but the parts of them near the envelope may be common. In step (3) it is preferable that the cathode should have been previously located accurately on the insulating member, so that, if the insulating member is always located similarly to the anode, the three said electrodes will be located correctly relative to each other.

According to a subsidiary feature of the invention, the anode of a device of the type specified is a disc pierced by a central hole and provided with a rim. The rim need not be; but preferably is, continuous; it may degenerate into a series of posts. The anode and control grid are supported independently of each other from the envelope, the grid being cylindrical and within the said central hole. The cathode is located Within the grid and supported from an insulating plate which rests on the said rim so that it forms a cover for the dish composed of the disc andrim.

The invention will now be explainedfurther with reference to the accompanying drawing which shows, by way of example; one embodi ment of the invention. Figure l isa longitudinal section of the relevant parts, of the completed tube; Figures 2, 3 and 4 are perspectiveviews of the anode, control grid, and cathode structures respectively.

5 is the re-entrant part of the glass envelope of the device through which the leads to the elec trodes are sealed. 2 is the lead to the control rid, which consists of a ring of wires 3 connecting an annulus i to the rim of a cap 5 which fits onto the end of the lead 2. After the leads have sealed through the wall, the first step is to fix the cap S onto the lead 2. The anode isa nickel disc new the edge of which is welded the nickel rim 8. It pierced with a central ar i s et when the i stricture tee and with smaller holes 8 through which the leads 9 pass with clearance. flhisclearance allows the position of the anode relatively to the grid tobe adjusted accurately; th position is finally fixed by Welding the lugs It; already fixed to the anode, to the leads 9.

The cathode properis ashort nickel cylinder 5 i, coated on the outside with activating material, attached to the bottom of a rather narrowerbut considerably longer Nichrome cylinder I2 with an outwardly directed flange l3 at the top. The

heater Hi lies between the cylinders II and I2;

one lead to it i5 passes through a hole in the cylinder 52; the other is the cylinder l2 itself continued by the wire it. The flange I3 is clamped between a mica disc it which rests on the top of the rim 6 and an upper mica disc [8. These discs are pierced with holes into which pins 29, upstanding from the anode disc is, fit closely so as to locate the mica discs, relative to which the cathode'is already accurately located,

accurately relative to the anode.

A nickel cylinder 25 surrounds and is connected to the lead 9, so that the anode and grid leads 9' and 22, within the tube form a concentric'line. Outside" the tube another cylinder 22 similarly forms a concentric line with the external partof' the lead The concentric line is interrupted wherethe leads pass through the wall l, but since here the space between theinner and outer mem bers is'occupied by glassof higher dielectriccon stantthan air, matters can be arranged so that there is little electrical discontinuity.

The following arethe chief dimensionsof the diameter 13 The tube will operate satisfactorily at frequencies up to 1500 megacycles.

It will be clear that many modifications may be made in the embodiment illustrated without departing from the invention and it is desired to include all such modifications within the scope of the appended claims.

What is claimed as new is:

1. In a thermionic discharge device, a base, lead-ins extending through said base, one of said lead-ins including a cylindrical support member, a control grid supported on said support member, an anode supported on two others of said lead-ins, said last-named lead-ins being electrically connected, a cathode, an insulating support comprising two spaced discs supported on said anode, said cathode having a flange extending between said discs for support thereby in insulated relation with respect to said anode, and a heater for said cathode, said heater being electrically connected to two others of said lead- 2. In a thermionic discharge device, a base, a cylindrical control grid supported on said base, an anode supported on said base independently from said control grid, said anode comprising a disc provided with a central opening, a rim projecting from a surface of said disc remote from said base, said central opening receiving said grid, a cathode, said rim supporting said cathode, said cathode being located within said grid, and leads to said grid and said anode forming a concentric line along at least one longitudinal portion of said leads.

3. A thermionic discharge device comprising an envelope, a base, a control grid, an anode independently supported on said base in spaced relationship to said control grid, and a cathode supported on said anode, said anode comprising an annular body defining a central opening therein, a cylindrical rim extending from said anode and coaxial with said opening, said control grid having a cylindrical form and entering said central opening in said anode, said cathode having a cylindrical form and entering said control grid, an insulating support member supporting said cathode, said insulating support member resting on said cylindrical rim.

. 4. A thermionic discharge device comprising a base, a control grid and anode independently supported on said base in spaced relationship, and a cathode supported on said anode, said cathode having an outwardly extending flange, said anode comprising an annular body defining a central opening therein, a cylindrical rim extending from said anode and coaxial with said opening, said control grid having a cylindrical form and entering said central opening in said anode, said cathode having a cylindrical form and entering said control grid, and insulating support member supporting said cathode comprising two insulating discs, said outwardly eX- tending flange on said cathode being clamped between said two insulating discs, said discs being supported on said cylindrical rim on the anode.

5. A thermionic discharge device adapted to operate at very high frequencies of the order of 1000 megacycles, including a base, an electrode assembly including at least one anode and control grid supported on said base, a lead to each of said anode and said control grid, said leads extending through said base from one surface thereof and emerging from an opposite surface thereof, said leads forming a concentric line along longitudinal portions thereof, a cathode, and two spaced insulating discs supported on said anode, said cathode including a flange, said flange extending between said discs.

6. An ultra high frequency thermionic discharge device adapted to operate at frequencies of at least 1000 megacycles comprising an envelope, a base, an electrode assembly supported on said base, said electrode assembly including a control grid, a cathode, and an anode, leadins extending through said base, said control grid being supported on one of said lead-ins, said anode being supported on two others of said lead-ins, said cathode being mounted on said anode and insulating means comprising two spaced discs between said anode and said cathode.

7. An ultra high frequency thermionic discharge device adapted to operate at frequencies of at least 1000 megacycles comprising an envelope, a base, an electrode assembly supported on said base and leads to said electrode assembly through said base, said electrode assembly comprising an anode, control grid and cathode, said anode and control grid being supported on said base by independent ones of said leads in a spaced relationship, and spaced insulating discs supported on said anode for supporting said cathode in a spaced relationship to said anode, whereby said anode, control grid and cathode are positioned in proper relationships, and two of said leads having concentric cylindrical portions forming a concentric line along at least one predetermined longitudinal portion thereof.

8. An ultra high frequency thermionic discharge device adapted to operate at frequencies up to 1500 megacycles comprising an envelope, at base, an electrode assembly supported on said base, and leads to said electrode assembly passing through said base, said electrode assembly comprising an anode, control grid and cathode, said anode and control grid being supported on said base by independent means, said cathode comprising a preformed structure including two spaced insulating discs, a ring on said anode for engaging said insulating discs to support said cathode, two of said leads forming a concentric line extending effectively from two of said elec trodes on one side of said base to a predetermined plane projected from the opposite side of said base.

GEOFFREY WILLIAM WARREN.

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

UNITED STATES PATENTS Number Name Date 1,736,275 Perryman Nov. 19, 1929 2,153,728 Southworth Apr. 11, 1939 2,207,846 Wolif Feb. 16, 1940 2,394,908 Gavin Feb. 12, 1946 2,404,113 Wagner July 16, 1946 2,411,184 Beggs Nov. 19, 1946 2,423,819 Chevigny July 8, 1947