US2523049A - Water-cooled multicircuit magnetron - Google Patents

Description

9 m. m w .e-n 5 ON 2, t5 o n .t ed .t w Vw A m 1mm@ m .n H. M Nmw QW. Owl mm2, z NUM im Rmm mm.. m Q 9 m MO n sept. 19, 1950 Patented Sept. 1.9, 1950 UNITED STATES PATENT. OFFICE WATER-COOLED MUL'TICIRCUITV MAGNETRJON Richard B. Nelson, Schenectady, N. Y., assignor to GeneralElectric Co'mpan a corporation of New York Application October 2, 1946, Serial No. 700,758

11 Claims.

My invention relates specifically to Water cooled vane type magnetrons and more generally to improved electric discharge devices of the magnetron type.

Magnetron devices including a plurality of coupled resonant circuits as an anode structure, have been developed for high frequency applications. My invention relates to an improved device of this character which is? particularly adapted for high power continuous wave applications and is Well suited for industrial applications such as dielectric heating. ter-:ine my invention contribute to a device which is rugged, relatively yeasy to manufacture, and wl'iich is easily connected with `the high irequency cil .uits with which it is used.

It is an object of my inventionto provide al new and improved electric discharge ldevice ofA the magnetron type.

It is another object of my invention to provide a new and improved resonant structure for electric discharge devices. A

For a` better understanding of my invention,

reference may be had to the following descrip-vr envelope I whichlmay to advantage be forme of copper or .other material which is essentially nonmagnetic. A circular array of anode elements 2 rto II, inclusive, are supported from the inner wall of envelope l in uniformly spaced radial relation. Each of the elements is, in the preferred embodiment, illustrated of substantially Usliaped in a radia plane and is` formed from rod-like st ck such as copper tubing. As illustrated in Fig. l, the open ends of the arms of each. Uasl'iapt-:d anode section communicate with IZ and I3 formed in the wall of the envelope. in order to'k facilitate manufacture, passages I2 and I3 areI formed by machining the cylindrical recesses in the' outer wall of the copper cylinder, and then completing the` passages by bracing to the envelope a sheet metal cylinder Id. As illustrated in Fig. 1, the upper passagev l2' communicates `with the fitting l5 through a longitudinal passage IS. A similar fluid passage I3! communicating with the cir-'f The features which charac` trode space.

complete a iluid circuit through the various anode sections.

In addition to providing for the eflicientfcool-y ing of the anode structiue, the particular form of the anode elements described also permits strapping of the anode in an improved manner. As illustrated in the drawing, a pair of ring straps El and i8 surround the longitudinal or portion of each U-shaped'ianode element. Strap I'i is electrically connected, as by brazing,

to each alternate anode section and strap I3 is j connected with the remaining anode sections. illustrated in Fig. 2, the strap I3 is connected' with the anode sections 3, 5, l, S and II.

ance connections between the interconnected anode sections and also minimizes the electrical dissymmetry usually produced by double strapping structures. As distinguished from usual types of ring strappingthe rings of the present invention both of the same diameter and are shielded from the cathode to a considerable extent by the :base portions of the anode sections. near the axial center of the anode sections and symmetricallyvwith respect to the cathode pro? a helical cathode i9 lccatedcentrally in the open?v ing supported from the envelope I by means including a terminal and lead-in structure. As illustrated in Fig. l, the upper end wall of the envelop@ is provided by an apertured metal member EEE which is in the shape of a truncated 44)' cone directed inwardly of the envelope. The member il@ is formed of material having low magnetic reluctance and in addition to providing a portion of the envelope provides a pole piece for producing a magnetic field in the interelecf A sheet metal disk or washer 2i isr secured to the exterior of the member 2li and pro vided with upstanding anges 22 and 23. The outer flange is bonded to the inner wall of the envelope to position and hermetically seal the pole piece to the envelope. The inner flange 2t is joined to a anged member 24 which surrounds the aperture in the pole piece 21| and provides a support for the cathode lead-in termi-v nals. As illustrated. an inner flange r25 on the member 24 is sealed to the lower edge of a cylinn Thisr 5arrangement' of straps provides very low lipped Also, the location of the rings' drical insulator 26. A metal sleeve y21, which provides one terminal for the filamentary cathode I9, is sealed to the upper edge of the insulating cylinder 26. The other terminal for the cathode is provided by a cylindrical member 28 closed at its outer end and sealed to the terminal 2'| by a cylindrical insulator 29. The upper terminal of the cathode is connected directly to the terminal 28 by an elongated conducting stud 39 Which is bonded to the inner end wall of the terminal 28. As illustrated, this stud is substantially smaller in diameter than the insulating cylinder 26 to permit the connection of the other terminal of the cathode I9 with the sleeve terminal 2`| by means of a conducting cylinder 3| interposed between the stud 3G and the insulator 26. As illustrated in the drawing, the lower terminal of the cathode is connected with a conducting end shield 33 which is, in turn, connected by a central post at 32 to an upper end shield 34. The upper end shield is connected with the cylinder 3| and as a result with the external terminal 27 by a conductor 35.

A vpole piece similar to the member 20 is provided directly below the anode structure by a member 36 of frusto-conical shape. This member is bonded to the inner wall of the envelope with the flattened central portion adjacent the interelectrode space. The members 2U and 35 cooperate with a coil 31 which surrounds the envelope to produce a magnetic lield between the anode and cathode which is substantially parallel to the axis of the cathode. It will be apparent that the wall of the envelope provides a magnetic shunt with respect to the interelectrode space, and for this reason it is desirable to utilize a material of high magnetic reluctance for the envelope and to provide a magnetic yoke 3'1 about the coil which terminates opposite the members 20 and 3S.

The envelope of the device is completed by a seal construction which provides concentric terminals for connection with an external high frequency circuit. A cup-shaped metal terminal 38 is supported centrally within the envelope and sealed thereto by a dome-like insulator 38 which is sealed at its lower edge to a cylindrical sheet metal member 40. The member 4Q terminates at its lower end in a ange 4| which ts Within a cylindrical extension of the envelope provided by a sheet metal ring 42. The llange 4| and ring 42 are bonded together to hermetically seal the envelope and support the sealing structure within the metal cylinder The central terminal 38 is conductively connected by a strap 43 with one of the anode sections 6. As illustrated, this strap extends through an opening 44 in the pole piece 36. The cup-shaped terminal 38 and the ring 42 provide concentric terminals which are adapted to connect the magnetron device with a concentric transmission line, through which the power produced by the device is conducted to a suitable load.

As will be readily understood by those skilled in the art, high frequency oscillations are produced by exciting the resonant structure provided by the various anode sections by means of a space charge produced in the region between the inner ends of the anode sections and the cathode and moving under the combined action of an electric eld produced by voltage applied between the anode and cathode, and the axial magnetic eld produced in the interelectrode space by coil 31 and cooperating pole pieces 2| and 36. It will be apparent from the description that the illustrated embodiment of my invention provides a magnetic device which is of relatively simple structure, which is adapted to be water-cooled, and which is easily plugged into both the coil for producing a magnetic field and the concentric terminals of an output circuit.

While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that changes and modifcations may be made without departing from my invention in its broader aspects, and I, therefore, aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. In a magnetron device of the resonator anode type, an anode structure including a cylindrical supporting envelope, a plurality of anode sections supported from the inner wall of said envelope and extending radially inwardly in circumferentially spaced relation, each of said anode sections comprising bent tubing having a substantially U-shaped section in a radial plane and having the open ends of the tubing of each section communicating with passages in the Walls of the envelope, and a pair of conducting rings threading the openings provided by said U- shaped anode sections, each being electrically connected with different alternate anode sections.

2. In a magnetron device of the resonator anode type, an anode structure including a cylindrical supporting envelope, a plurality of anode sections supported within said envelope and extending radially -inwardly in circumferentially spaced relation and providing a plurality of cavity resonators, each of said anode sections comprising bent tubing' having a substantially U-shaped section in a radial plane and each having the arms thereof extending outwardly, and means supported from the side wall of said envelope providing passages communicating with the outwardly extending open ends of the tubing forming said sections. v

3. In a magnetron device of the resonator type, an anode structure including a cylindrical supporting envelope, an even number of anode sections supported within said envelope and extending radially inwardly and in circumferentially spaced relation, each of said anode sections comprising bent tubing having a substantially U- shaped section in a radial plane, said sections having the base'portions thereof extending in an axial direction and in circumferentially spaced relation and dening a central opening of the anode structure, and a pair of conducting rings threading the openings provided by said U-shaped anode sections, one of said rings being connected with the even number anode sections on the side of the base portions away from the central opening and the other of said rings being connected with the odd numbered anode sections on the side of the baseportions away from the central open; ing.

4. In a magnetron device of the resonator anode type, a cathode, an anode structure comprising a plurality of anode sections extending radially inwardly in circumferentially spaced relation to provide a circular array, each of said anode sections having an aperture therethrough which is symmetrical with respect to a central plane through said anode transverse to the axis of the circular array, and a pair of conducting rings threading said apertures with each ring on a diilerent side of said central plane with a portion of each of said anode sections interposed between said rings and said cathode, one of said rings being connected with alternate anode sections and the other of said rings being connected with the remaining anode sections.

5. In a magnetron device of the resonator anode type, an anode structure comprising a plurality of anode sections, a support, said anode sections being mounted within said support and extending radially inwardly to provide a circular array of anode sections, each of said sections having an aperture therethrough dei-med in part by axially extending portions at the inner ends of the anode section, and a pair of conducting rings of equal diameters threading said apertures with each ring positioned on opposite sides of a plane extending through said anode structure at the longitudinal center thereof and in a direction perpendicular to the longitudinal axis thereof, one of said rings being connected with the axially extending portions of alternate anode sections on the sides thereof facing said apertures and the other of said rings being connected with the axially extending portions of the remaining anode sections on the sides thereof facing said apertures.

6. In a magnetron device of the resonator anode type, an anode structure comprising a plurality of anode sections extending radially inwardly in circumferentially spaced relation7 each of said sections having an aperture therethrough, said apertures being dened in part by axially extending portions of said anode sections located at the inner ends thereof, and a pair of conducting rings threading said apertures and positioned on opposite sides of a plane passing through the center of said anode sections in a direction perpendicular to the axis thereof, one of said rings being connected to the axially extending portions of alternate anode sections on the side thereof facing said apertures, and the other of said rings being connected with the axial portions of the remaining anode sections on the side thereof facing the apertures therethrough.

7. In an electric discharge device of the magnetron type comprising a generally cylindrical envelope, an anode structure supported within said envelope intermediate the ends thereof and including a plurality of circumferentially displaced cavity resonators, an end wall for said envelope including a pole piece, a second pole piece supported on the opposite side of said anode structure within said envelope and a closure at the other end of said envelope including a concentrically located terminal and an annular sealing member housed within said envelope and means extending through said second pole piece coupling ,said central terminal with said anode structure. a

8. In an electric discharge device of the magnetron type comprising a generally cylindrical envelope, an anode structure supported within said envelope intermediate the ends thereof and including a plurality of radially extending anode sections dening a plurality of circumferentially displaced resonator elements, an end wall for said envelope including a pole piece, a second pole piece supported from said envelope on the opposite side of said anode structure within said envelope and a closure for the other end of said envelope including a concentrically located ter- Iii minal and an annular sealing member located on the side of said second pole piece remote from said anode and housed within said envelope, and means coupling said central terminal with said anode structure.

9. In an electric discharge device of the magnetron type comprising a generally cylindrical envelope, an anode structure supported within said envelope intermediate the ends thereof and including a plurality of circumferentially displaced resonator structures, an end wall for said envelope including a pole piece having a frusto conical shape, a second pole piece of frustoconical shape supported on the opposite side of said anode structure and secured to the inner wall of said envelope, a closure at the other end of said envelope including a concentrically located terminal and a sealing member interposed between said terminal and the wall of said envelope, and a conductor coupling said central terminal with said anode structure and providing with the wall of said envelope a concentric transmission line section.

10. In an electric discharge device of the mag"- netron type comprising a generally cylindrical envelope, an anode structure supported within said envelope intermediate the ends thereof and including a plurality of circumferentially displaced resonator structures, a closure for one end of said envelope including a concentrically located terminal and a sealing member interposed between said terminal and the Wall of said envelope, and a conductor coupling said central terminal with said anode structure and providing with the wall of said envelope a concentric transmission line section.

11. In an electric discharge device of the magnetron type comprising a generally cylindrical envelope, an anode structure supported Within said envelope intermediate the ends thereof and including a plurality of circumferentially displaced resonator structures, a closure at one end of said envelope including a concentrically located terminal and a sealing member interposed between said terminal and the wall of said en" velope and housed within said. envelope, and a conductor coupling said central terminal with said anode structure and providing with the wall of said envelope a concentric transmission line section.

RICHARD B. NELSON.

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

UNITED STATES PATENTS Number Name Date 2,163,157 Samuel May 20, 1989 2,189,501 Helbig Feb. 6, 1940 2,411,299 Sloan Nov. 19, 1946 2,414,085 Hartman Jan. 14, 1947 2,422,465 Bondley June 17, 1947 2,446,531 Derby' Aug. 10, 1948 2,485,401 McArthur Oct. 18, 1949 FOREIGN PATENTS Number Country Date 509,102 Great Britain July 11, 1939

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