US2431273A

US2431273A - Electron discharge device employing a cavity resonator

Info

Publication number: US2431273A
Application number: US531312A
Authority: US
Inventors: Leon S Nergaard
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1944-04-17
Filing date: 1944-04-17
Publication date: 1947-11-18
Anticipated expiration: 1964-11-18

Description

s. NERGAARD 2,431,273 ELECTRON DISCHARGE DVICE EMPLOYINGA GAVITY RESONATOR Nov. 18, 19477 Filed Aprillv, 1944 5 Sheets-Sheet 1 fa l f l 9 Z w NJ. HHH a .3 n Z H Q Z f\/ I 3)( J f f d? 5 /J 0 mb Z ,2 A 1 ,n 5 l oO l A 5 0d I 5f! Il: @n MAIl..

Nov. 18, 1947. s, NERGAARD ELECTRON DISCHARGE DEVICE EMPLOYING A CAVITY RESONATOR 3 sheets-sheet? Filed April 1'7, 1944 Snventor Gttorneg Nov. 18,y 1947.V 1 s, NERGAARD 2,431,273

ELECTRON DISCHARGE DEVICE EMPLOYING A CAVITY RESONATOR` Filed April 17, 1944 3 Sheets-Sheet 5 :inventor (Ittorneg Patented Nov. 18, 1947 ELECTRON DISCHARGE DEVICE EMPLOY- ING A CAVITY RESONATR Leon Nergaard, Princeton, N. J., assigner to Radio Corporation of America, a corporation of Delaware Application April 17, 1944, Serial No. 531,312'I 19 claims. 1

My invention relates to apparatus useful at ultra-high frequencies and more particularly to electron discharge devices and associated circuits of the cavity resonator type.

An object of my invention is to provide an electron discharge device and associated circuit particularly suitable for high frequency operation and capable of delivering large amounts of power.

Another object of my invention is to provide an electron discharge device which can deliver large amounts of power at high frequencies, but which -1s nevertheless small and compact, has few parts, and lends itself readily to manufacture.

A more speciiic object of my invention is to provide an electron discharge device in which the electrodes although closely spaced are firmly and rigidly supported with respect to each other.

A further object of my invention is to provide an electron discharge device having electrode leads and supports which will merge into high frequency circuits of the cavity resonator type so that the internal reactances may be coupled smoothly to the external reactances which complete the circuit and thus reduce radio frequency losses and spurious modes of oscillation to a minlmum.

Another vspecific object of my invention is to provide a cathode which will promote heater power economy.

A further object of my invention is to provide a cavity resonator circuit in which the circuit has large ldimensions while permitting operation at very high frequencies.

Another vobject of my invention is to provide an electron discharge device and associated circuits comprising cavity resonators which provide a novel method of introducing biasing voltages on the electrodes enclosed within the cavity resonators.

A further object of my invention is to provide improved means for connecting the terminals of an electron discharge device to a cavity resonator circuit.

Another object of my invention is to provide push-pull circuits for an electron discharge device made according to my invention and using a novel type of coaxial line resonator.

A still further object of my invention is to provide an electron discharge device of the type described above utilizing a novel cavity resonator circuit associated therewith and novel means for cooling the device during operation.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims, but the inven-v tion itself will best be understood by reference to the following description taken in connection with the accompanying drawing in which Figure 1 is a longitudinal section of an electron discharge device and associated circuit made according to my invention; Figure 2 iS a longitudinal section of an electron discharge device made according to my invention and of the type utilized in Figure l; Figure 3 is a longitudinal section of a modification of the electron discharge device and associated circuit shown in Figure 1, and Figure 4 is a longitudinal section of the electrondischarge device shown in Figure 3. f

In accordance with my invention I provide an electron discharge device having an indirectly heated cathode I0 of cup-shape surrounded by a cup-shaped grid II, both nested within anode I2 provided with longitudinally extending heat radiating ns I3. The anode provides part of the envelope and is provided with a collar I4 of U- shaped transverse section. aThe outer rim of the collar ll is sealed to the insulating collar I5. The header for the tube envelope includes a disc member i9 welded at I1 to a collar I 6 sealed to the other end of insulating collar I5. The disc or header is is provided with collar I8 sealed by means of a transverse flat press 20 through which the leads i3 extend. These leads support the conducting collar 2l on which the cathode is mounted. The grid is supported by means of cone-shaped collar 22 mounted on the disc I9. This device will be described in more detail below in connection with Figure 2.

An input circuit of the coaxial line type providing a cavity resonator is coupled to the device described and comprises an inner tubular member 25 capacity coupled to the cathode leads. A collar 28 provides the cathode lead socket and is capacity coupled toy the tubular member 25 through the insulating collar 2S, preferably of mica. The outer tubular member 26 is connected to the inner tubular member by closure member 2l. The outer tubular member is provided with a plurality of spring fingers 32 engaging the outer periphery of the header member I9, upon which the grid is supported and toy which it is electrically connected. A snorting member 3| tunes the circuit. rihus the cavity resonator is coupled between the grid and cathode of the electron discharge device.

The output circuit is a novel push-pull cavity resonator type and comprises an inner tubular member 35 which receives within one end the radiating iins i3 and the anode I2 of the electrQIl discharge device and the outer tubular member 38 surrounding the inner tubular member. This circuit can operate in a half wave mode or a multiple thereof depending upon the adjust- `ment of the cathode circuit.

At the other end of the output cavity resonator is a second electron discharge device of the type rst described. A coaxial input circuit 25 identical with that connected to the electron discharge device rst described is coupled to the cathode and grid of this second electron discharge device and the member 35 receives within it the anode I2 and radiating ns I3.

The outer tubular member 38 of the cavity resonator has an aperture 31 through which tubular member 36 extends, this member being connected electrically to the inner tubular member 35 of the cavity resonator. This tubular member 36 serves as a lead for the anode voltage and also as a duct for directing cooling air inte the inner member 35 and out into the outer member past the longitudinally extending cooling iins I3 and I 3 over the insulating collar members I and I5', and back out through the aperture 31. The output may be taken by means of a coaxial liner comprising inner conductor 35 and outer conductor 38'. Feedback may be of any type but is shown as a coaxial coupling line coupled between the input and output circuits and including an inner conductor 25 and an outer conductor 26".

- The electron discharge device uti1ized :in my one end of which is connected to the cathode and theother end of Which is connected by means of lead IIJ to a lead wire 48' `sealed through the press 20. The lead-in'conductors 48 mounted in a circle are enclosed within and connected to a supporting cathode collar 2l, the cathode proper being supported' by means of ribbon-like conducting members 41 to reduce heat conduction between the cathode and collar 2I. The grid II is provided with a top cap II' having a plurality of apertures I l'f for reducing heat iiow from the center of the cap to the grid wires. The top cap has ,a cathode-grid aligning hole in the center through which the conductor 49 from the cathode i extends and is supported from the top cap by means of the insulating tubular member 53, The grid I I is iirmly and rigidly supported by means of the cone-shaped member 22 sealed to the header member I3, which may be a fernico ring.

V'Ihe cathode may b e of silicon nickel ribbon coated on the surface with the usual carbonates.

'Ihe lower end of the cathode thimble is closed by heat shield 46. tungsten wire and cylinder 2| may be nickel and The heater ID' may beof thev supporting tabs 41 may be of copper plated kovar, the tabs serving to heat insulate the cathode Vas well as provide electrical contact. There is no contact between the sleeve 2I and the heater lead 48' to which the cathode heater lead I0" is connected.A The getter pellet 5 I may be connected between the lead 49 and the cathode cylinder ZI to provide a flashing circuit.

As pointed out above, the grid and cathode are enclosed within the anode I2 provided with -the 7 vertical or longitudinally extending heat radiating ns I3, the anode being a copper thimble to which may be silver soldered the kovar sealing collar or ring I4 of Ytransverse U-section. The envelope is completed by means of the insulating c ollar I5, preferably of glass sealed to the outer 11p of collar I4 and the collar I6A which is provided with a iiange I6 welded at I1 to the disc I9 of the header. With the arrangement shown the cathode and grid can be first mounted on the header member, and the anode assembly sealed thereover to disc I3 by welding. This would avoid the necessity employed in one meth- `od of assembly iirst requiring forming the envelope, cracking the collar I5 and re-sealing the same after mounting the cathode and grid upon the header. In the arrangement shown there is no danger of cracking of the button stem, due to uneven heating which would occur in re-sealing a cracked envelope collar I5.

The apparatus described can function at very high frequencies, of the order of 1200 megacycles or higher and deliver large amounts of power although occupying small space, which is of importance in certain applications, and permits adequate cooling. The tube and circuit merge into each other to provide an eicient high frequency apparatus. The cavity resonator circuits, despite the high frequency at which the apparatus is' designed lto operate, are of reasonable size providing desirable external reactances which can be tuned. i

In Figure 3 I show a modication of an electron discharge device and associated circuit made according to my invention. This is a single tubeY circuit utilizing a tube muchlike that shown in Figure 2. The grid-anode circuit againrof theY coaxial line type consists of the inner tubular member 25", the outer tubular member 23, closure member 2,1 coupled between the cathode l0 and grid I I, and the shorting tuning ring 3I.

The output circuit now comprises the inner conductor 46 having a slidable collar 41' Yfor determining the length of the inner tubular meminner and outer tubular'members to direct the iiow of cooling Vair which is admitted; at extension 6I into proper channels. The upper end of the member 48" is provided with an aperture surrounded by collar 54 through which the inner conductor 55 of the coaxial line,'comprising conductors 55 and 55', extends, the aperture being sealed by insulating member 56, Vand thelowerr end of the coupling member 55 extending within the rcollar 41' for coupling the coaxial line to the output circuit. The cooling medium may be directed through the extension'l along the lines indicated by the arrows for the iiow of the cooling medium, past springs 32 into the input circuit, past tuning ring 3l' and rods 3l.V may operate in a half wave mode or a multiple thereof.

In Figure 4, showing details, is a modication of the electron discharge device shown in' Figure Y 2. Like members designate like parts. The cathode'heater 51 is slightly different Yand the header member compris/es ring I5 andis provided'withV oppositely directed

flanges

53 and 53, the press being supported within and Ysealed to the flange '58, the flange 59 beingV sealed to the insulating collar I5.

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

What I claim as new is:

1. An electron discharge device having an anode, a grid and a cathode, resonator means coupled between the cathode and grid, vand a cavity resonator coupled between said grid and anode and having an inner conductor coupled to said anode and comprising an elongated member engaging and extending from said anode, and a hollow member surrounding the elongated member but out of electrical contact therewith but enclosing said elongated member, said hollow member having an aperture therein and means extending through said aperture and connected to said inner conductor for applying a voltage to said inner conductor.

2. An electron discharge device having an envelope closed at one end by an anode forming part of the envelope for said electron discharge device, a grid within said envelope having conducting means extending radially through said envelope and supporting said grid and a cathode within said envelope having conducting means extending through said envelope, a cavity resonator coupled between the cathode and grid conducting means and a cavity resonator coupled between said grid and anode and having an inner conductor coupled to said anode and comprising an elongated member having one end engaging and extending from said anode and a hollow member surrounding the elongated member but out of electrical contact therewith and enclosing said elongated member, said hollow member having an aperture oppositely disposed to the free end of the elongated member and electrically conducting means extending through said aperture and coupled to said elongated member.

3. An electron discharge device having an anode, a grid having conducting means extending therefrom, and a cathode having conducting means extending therefrom, a cavity resonator coupled between the cathode and grid conducting means and an output cavity `yresonator coupled between said grid and anode and having an inner conductor coupled to said anode and compri-sing an elongated member engaging and extending from said anode, a tubular member surrounding the elongated member but out of electrical contact therewith and completely enclosing said first tubular member, said second tubular member having an aperture therein, and electrically conducting means extending through said aperture and coupled to the interior of the output cavity resonator.

4. An electron discharge device having an envelope closed at one end by an anode forming part of the envelope for said electron discharge device, a grid within said envelope having conducting 4means extending `radially through said envelope and a cathode within said envelope having conducting means extending through said envelope, a cavity resonator coupled between the cathode and grid conducting means and an output cavity resonator coupled between said anode and grid and comprising an inner tubular member engaging and extending from said anode, an

outer tubular member coupled .to the grid conducting means .and surrounding the inner tubular member but out .oi electrical contact therewith and .completely enclosingfsaid inner tubular member, said outer tubular member having an aperture oppositely disposed to the free end of the in- -ner tubular member and electrically conducting .means extending through said aperture and coupled to the free end of said inner tubular mem'- ber.

. 5. A high frequency apparatus comprising Aa pair of concentric tubular members, the inner of said tubular members being open at its ends, said outer tubular member having apertures in the -ends thereof, a pair of electron discharge devices, each electron discharge device having an .anode and extending through an aperture in one end of said outer tubular member and `'having its anode extending within an open end of said inner tubular member and engaged thereby, each of said electron discharge devices including a grid coupled to said outer tubular member, and a cathode, and a cavity resonator coupled between the grid and cathode of each of said electron discharge devices, said outer tubular member having an aperture therein and a voltage lead extending through said aperture and contacting said inner tubular member.

6. A high frequency apparatus including a pair of oppositely disposed electron discharge devices each including an anode forming part of the envelope of the electron discharge device, said anodes being provide-d with longitudinally extending radiating fins and a cavity resonator coupled between said electron discharge devices and including an inner tubular member having open ends, the anode of one of said electron discharge devices being positioned within and engaged by one end or" sai-d inner tubular member and the anode of the other of said electron discharge devices being within and engaged by the other end of said inner tubular member, and an outer tubular member surrounding said electron discharge devices and said rst tubular member, and a tubular member extending through but out of contact with said outer tubular member and opening into the interior of said interior of Sai-d inner tubular member for directing a cooling medium within said inner tubular member and past said radiating ns of said electron discharge devices.

'7. A high frequency apparatus including a pair of oppositely disposed electron discharge devices each including an anode, a grid and cathode, said anodes forming part of the envelope for said electron discharge devices and having longitudinally extending radiating iins and a cavity resonator coupled between said electron discharge devices and including an inner tubular member having open ends, the anode of one of said electron discharge devices being positioned Within and engaged by one end oi' Isaid inner tubular member and the anode of the other of said electron discharge devices being Within and engaged by the other end of said inner tubular member, and an outer tubular member surrounding said electron discharge devices and said rst tubular member and coupled to the grids of said electron discharge devices, and a tubular member extending through but out of contact with said outer tubular member and opening into the interior of said inner tubular member for directing a cooling medium within said inner tubular member and past said radiating fins of said electron discharge devices.

8. A high frequency apparatus comprising a pair of concentric tubular members, the inner one of said tubular members being open at its ends, the outer tubular member having apertures in the ends thereof, an electron discharge device having an anode extending through the aperture in each end of said outer tubular member and having its anode extending within an open end of said inner tubular member andengaged thereby, each of said electron discharge devices including a grid coupled to ysaid outer tubular member and having a cathode and a resonator means coupled between the grid and cathode of each of said electron discharge devices.r

9. A high frequency apparatus including a pair of oppositely disposed electron discharge devices each including an anode, a grid and cathode, said anodes forming part of the envelope for said electron discharge devices and having longitudinally extending radiating fins and a cavity resonator coupled between said electron discharge devices and including an inner tubular member having open ends, the anode of one of said electron discharge devices being positioned within and engaged by one end of said inner tubular member and the anode of the other of said electron Vdischarge devices being within and engaged by the other end of said inner tubular member, and an outer tubular member surrounding said electron discharge devices and said rst tubular member and coupled to thegrids of said electron discharge devices, and cavity resonators coupled between the grids and cathodes of each of said electron discharge devices, and a tubular member extending throughV but out of contact with said outer tubular memberA and opening into the interior of said inner tubular member for directing a cooling medium within said inner tubular member and past said radiating iins of said electron discharge devices.

l0. A high frequency apparatus including a pair of oppositely disposed electron discharge devices each including an anode forming part of the envelope for said device, a grid and cathode, a radially extending grid conductor extending through the envelope and a cathode conductor extending through the envelope, said anodes being provided with longitudinally extending heat radiating fins and a cavity resonator coupled between said electron discharge devices and including an inner tubular member having open ends, the anode of one of said electron discharge devices being positioned within and engaged by one end of said inner tubular member and the vanode of the other of said electron discharge devices being within and engaged by the other end of said inner tubular member, and an outer tubular member surrounding said electron discharge devices and said first tubular member and coupled to the grid conductor, and cavity resonators coupled between the grid and cathode conductors of each of said electron discharge devices.

11. A high frequency apparatus including a pair of oppositely disposed electron discharge devecies each including an anode forming part Vof the envelope of said electron discharge device, said anode being provided with longitudinally extending radiating ns, and a cavity resonator coupled between said electron discharge devices and including an inner tubular member havingY open Yends, the anode of one of said electron dis-r charge devices being positioned within and engridsv withinthe envelopes, and an outer tubular member surrounding said electron discharge devices and said first tubular member, said outer tubular'member being coupled to the grids of said electron discharge devices and a tubular member extending through but out of contact with said outer tubular member and opening into the interior of the inner tubular member for directing a cooling medium within said inner tubular member and past said` radiating fins `of said electron discharge devices and :resonant means connected between the cathode and grid of each of said electron discharge devices.

12. An electron discharge device having an anode and a cathode, said anode forming part of the envelope of said electron discharge device, a cavity resonator coupled to said electron discharge device and including an inner tub-ular member having one end engaged with the anode of said electron discharge devicev and an outer tubular memberl surrounding said electron discharge devicel and said inner tubular member and having an aperture oppositely disposed to the free end of said inner tubular membenand a coaxial line having inner and outer conductors, the inner conductor extending through said aperture toward the free end of said inner tubular anode, a gridrand cathode, said anode forming part of the envelope of said electron discharge device, a cavity resonator coupled to said electron discharge device and including an yinner tubular member having one end engaged with the anode of said electron discharge device and an outer tubular member surrounding said electron discharge device and said inner tubular member and coupled to said grid and having an aperture oppositely disposed tothe freev end ofV said inner tubular member, and a coaxial line having inner and outer conductors, the inner conductorextending through said aperture toward the free end of said inner tubular member. v

`V14. An electron discharge device having an anode and a cathode, said 4anode'forming part of the envelope of the electron discharge device and Y electronV discharge device and including an inner gaged by one end of said inner tubular member 1V and the anode of the other of said electron discharge devices being within and engaged by the VVother end of said inner tubular member, said electron discharge devices having cathodes and hollow member having one end surrounding and Y' engaged with the ns on said'anode and an outer Y hollow member surrounding said electron discharge device and said inner hollow member,

the inner hollow member opening into the interior of said outer hollow member, saidV outer hollow member having an aperture therein `and tubular means opening into said inner hollow;

member for directing a cooling medium through the Iaperture in said outer hollow member through said inner hollow member past said fins.

15. An electron 'discharge device having an anode, a grid and cathode, said anode, forming part of the envelope of said electron discharge device, a cavity resonator coupled to said electron discharge device and including an inner conducting member having one end' engaged withthe anode of said electron 'discharge device and an outer tubular member surrounding said'ele'ctron discharge device and said inner conducting member and coupled to said grid and having an aperture oppositely disposedto the free end of v'the inner conducting member, a coaxial line opening into said aperture and including outer and inner conductors-'the inner conductor of said coaxial line extending through said aperture toward the free end of said inner conducting member and resonant means coupled to said cathode and said grid, said outer tubular member having a second aperture, and a lead extending through said second aperture and contacting said inner conducting member.

16. An electron discharge device having a header member including a collar having a radially directed flange and an insulating member extending across and within said collar and sealed thereto on the inner surface only of said collar, a plurality of lead wires sealed through said insulating member, a cathode supported solely on said lead wires, a cup-shaped anode positioned over said cathode and a collar of insulating material sealed between said flange and the open end of said cup-shaped anode.

17. An electron discharge device having a header member including a collar having a radially directed flange .and an insulating member extending across and within said collar and sealed thereto, a plurality of lead wires sealed through said insulating member, a cathode supported on said lead wires, an elongated tubular member having a lip sealed to said Ilange, a grid surrounding said cathode mounted on said elongated tubular member, a cup-shaped anode positioned over said cathode and grid and a collar of insulating material sealed between said flange and the open end of said cup-shaped anode.

18. An electron discharge device having a header member including a rst collar having a radially directed flange and an insulating member extending across .and within said first collar and sealed thereto, a plurality of lead wires symmetrically arranged and sealed through said insulating member, a cup-shaped cathode supported on said lead Wires, an elongated tubular member having a lip sealed to said ilange, a grid surrounding said cathode and mounted on said tubular member, a cup-shaped anode positioned over vsaid anode and grid and having a collar of U-shaped transverse section at its open end, the inner lip being sealed to said anode, a second collar having `a iiange sealed to the flange of the first collar, and a collar of insulating material sealed between the outer lip of said U-shaped collar and the second collar.

19. An electron discharge device having a header member including a collar having a radially directed flange and an insulating member extending across and within said collar and sealed thereto, a plurality of lead Wires sealed through said insulating member, a cathode supported on said lead wires, an elongated tubular member having a lip sealed to said flange, 4a grid surrounding said cathode and mounted on said tubular member, a cup-shaped anode positioned over said anode and grid and a collar of insulating material sealed between said ilange and the open end of said cup-shaped anode, said cathode and grid comprising cup-shaped members, said grid including a, cap having an aperture therein and means extending from the cathode through said aperture positioning said cathode relative to said grid, said means being insulated from said cap.

LEON S. NERGAARD.

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

UNITED STATES PATENTS Number Name Date 2,404,363 Chevigny July 23, 1946 2,283,895 Mouromtsei et al. May 19, 1942 2,353,743 McArthur July 18, 1944 2,367,332 Bondley Jan. 16, 1945 Disclaimer 2,431,273.Leon S. Nergaard, Princeton, N. J. ELmemRoN DISCHARGE DEVICE EMPLOYING A CAVITY RESONATOR. Patent dated Nov. 18, 1947. Dsclaimer filed Aug. 5, 1949, by the assignee Radio Corporation of America. Hereby enters this disclaimer to

claims

3, 6, 7, 9, 10, 11, and 14 of said patent.

[Qicial Gazette Sept. 13, 1.949.]