US2606307A

US2606307A - Tunable magnetron

Info

Publication number: US2606307A
Application number: US644164A
Authority: US
Inventors: Marshall C Pease; Frank A Record
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-01-29
Filing date: 1946-01-29
Publication date: 1952-08-05
Anticipated expiration: 1969-08-05

Description

g- 1952 M. c. PEASE ET AL 2,606,307

TUNABLE MAGNETRON Filed Jail. 29, 1946 FIG.2

FIG?) INVENTOR. MARSHALL c. PEASE FRANK A. RECORD ATTORNFY Patented Aug. 5, 1952 UNITEDfSTATQES PATENT;QQFFICE V TUNABLE MAGNETRONY Mars'hall' bl l'ease, Boston, Mass, and Frank A.

Recordfrot'sdamg N. Y., assignors to the United States of Americ'aas represented by the secre- .tary: of "War:

imi ates inner} 29, 1946, Serial No. 64 4.164;

and more particularly to'improvement's in tuneable magnetron radio frequency oscillators.-

Various methods of tuning magnetron radio frequency oscillators; have beendevised in the past. Many of these methods weredesigned to change the frequency by coupling some externally tuned reactance into the magnetron resonant cavity. These designs were accompanied by a certain amount of unavoidablepower loss in the tuning reactance and in the intermediate coupling between the reactance and the magnetron cavity.

An object of the present invention is to provide a magnetron with a mechanical adjustment for the resonant frequency of the magnetron cavity resonators. I I V A further object of the inventionis to' accomplish tuning of a magnetron'with negligible Other objects and advantages of the--invention will be apparent during the course of the following description.

In the accompanying drawing forming a part of this'specification and in ,which like numerals are employed to designate like parts throughout the same,

Fig. 1 is a top view of a tuneable plural cavity magnetron embodying the principles of the principles or the present invention, with the'top cover removed showing the anode structure and a portion of the body structure broken away to illustrate the plunger rod. The bellows isshown partially cross-sectioned; the plunger rod is not cross-sectioned. I

Fig. 2 is a side view of hejanode structure itself.

Fig. 3 is a top view of one of the fixed metallic laminations composing the anode structure of Fig. 2.

Fig. 4 is a top view of one of the moveable metallic laminations composing the anode structure of Fig. 2.

Referring to Fig. 1 wherein is shown a preferred embodiment of this invention, the numeral I0 designates a substantially rectangular parallelepiped structure with one semi-cylindrical end which serves as the housing for the plural cavity magnetron concentrically disposed about central cathode I2 is the substantially cylindrical anode structure I3. Anode structure l3 contains a plurality of individual oscillator cavities 4 leading by radial off-center slots l5 into the cathode-anode space l6 which is concentrically disposed about cathode l2.

- fiCl'aimsiiCl. 315-40) E.

Fig. 2 shows aside view oftheanode structure l3 removed from magnetron Anode structure I 3 is composed of a plurality of metallic washer-like laminations 20, 2|, and 22 pleted anode structure l3.

Alternate metallic laminations 2|] composing I anode structure l3 are fixed laminations and the other laminations 2| and 22 are moveable corresponding to the cavities H of Fig. 1 and radial slots l5" corresponding to the radial slots |5 of Fig. 1. 'A 'fixed-pivothole 29 is provided on a boss 30 which projects from the circumference of moveable lamination. A second boss 3| projecting from thecircumference of laminations 2| has a tie hole 32 and a pivot slot Moveable l'aminations' 22 (Fig. 2) are identical with moveable laminations 2|, as shown in Fig. 4, save that the boss 3| extends only slightly beyond tie hole 32as shown by the dotted line in Fig. 4. a

Referring again to Fig. 1, a fixed-pivot pin 40 passes through the fixed-pivot hole 29 of the moveable laminations 2| and 22. A tie bolt 4| passes through the tie holes 32 of the moveable laminations 2| and 22 to maintain their alignment. A moveable plunger rod 42 passes between the uppermost andlowermost moveable laminations 2|. A pivot pin 43 is affixed to rod 42, said pivot pin 43 being guided in the pivot slots 33 of moveable laminations 2|. Moveable plunger rod 42 has a slot 44 which is guided by the fixed pin 45. Fixed pin 45 is aflixed to resonant frequency of each cavity 11 and. hence i of the frequency of the magnetron II.

A tuning range of the order of is readily attainable by the use of this device. lfhe inanifold variation, which alters the dimensions of each cavity I4 and of each sIOtxiI5,-JS noteworthy as causing a large change ,of -freqiiency'rorfa small rotation of the moveable"laminations 2| with respect to the fixed laminations 20. The power output is not appreciably -afi'e(= -,v J;

While there has been described what is at it:

ment of this inventionflit will be obvious that variou changesand modifications may be made therein withoutsdeparting:ifrom' the scope of the invention; J: a 1

, Whatisclaim'ed isf:

1. A 'tuneable magnetron oscillator including a substantially cylindricahan'ode structure, an evacuated housing surrounding saidranode:structure: said anode Structure having a central-cylindrical space surrounded by a pluralityr of concentrically arranged cylindrical cavities about said spacez-"an'd opening into said space through radial-slots, said anode/structure comprising va stack of metallic'washer'likelaminae tions, alternate laminations in saidistack being moveable withlrespect' to',the..others, a plunger.

rod connected with said inoveable laminations, vacuum seal means flexibly connecting said plunger rod to said housing, andrexternal tuning drive means connected to said zplunger rod,

wherebysaid plunger rod may be moved thereby quency of said magnetron oscillator;

2. Atuneable magnetron including a 'substan-z tially cylindrical anode structure, said anode" rtrueture' having. a, central cylindrical 1' space surrounded by, a plurality of cylindrical cavities concentrically arranged :about said :space and opening into said space'qthrough radial i slots, anode structure comprising a stack of allic g washerelike laminations, alternate a to h o rs-and mean -con e t o i ii moveablezlaminations; for movingsaidmoveanode structure comprising :a stack of. metallic inationsin; said; stack; being; moveable, with i -.40 moving said moveable jlaminations' with. respect I to said- :fixe'd j laminations -and' varying :the' di I mensions of; said cylindricalicirfltis and said"; radial slots andco'nsequently Evarying the fre-wi 4 laminations, alternate laminations in said stack being moveable with respect to the others and means connected to said moveable laminations for moving them into said cavity resonators to thereby vary the resonant frequency of said cavity resonators.

In ,a tunealile magnetron,,an anode structure having a plurality'of cavity resonators, said anode structure comprising a stack of metallic laminations, a number of the laminations in said stack being moveable with respect to'the others and means connected to said movable laminations for moving them into said cavt ity resonators' o thereby vary the resonant frequency 01'- said cavity resonators.

5. A tune'able magnetron including a substan- .,tially cylindr1cal anode structure having a central cylindrical space surrounded by a plurality present considered t bemthe preferred m di; oif cylindrical cavities concentrically arranged about said space and opening into said space through radial. slots, said anode structure comprising a stack of metallic washer-like laminations,.;alternate laminations in said'stack being movable with respect to the others, ,,and means connected to said movable laminations-for rotating said movablev laminations with respect to the other laminations to I thereby .constrict each of said cylindrical cavities and said ,radial slots.

6. A tunable magnetronoscillator having an anode structure said anode structure comprising substantially indentically shaped washer: like laminations, each-ofsaid laminationsbeing circular in cross-section and having a central circularspace surrounded by a plurality of cir cular holes concentrically arrangediabout said space and opening into said space through radial slots, all of said laminations being'arranged in a stack with saidspaces, said-holes and said slots insubstantial, coincidence, alternate laminations in said stack being rotatably movable with respect to theothers, and. means connected to said movable laminations forrotating said movable laminations with respect to said other laminations. v

l MARSHALL C.' PEASE.

-FRANK A, RECORD appearances CITED The following references areof record-in; the file of this patent:

UNITED STATES; PATENTS Spencer Apr. 5, 1949