US2454306A

US2454306A - clifford et au

Info

Publication number: US2454306A
Authority: US
Publication date: 1948-11-23
Anticipated expiration: 1965-11-23

Description

Nov. 23, 1948.

n. e. CLIFFORD ETAL v TUNABLE GENERATOR FOR ULTRA HIGH FREQUENCIES Filed Dec. 30, 1942 4) 1 1 'mr I) M v INVENTORS ATTORNEY Pat ented Nov. 23, 1948 a UNIT-ED STATES iPA l ENT osmos l .TUNABLE ,GENERATORTQRULTRAMIGH t FREQUENCIES v t *Davitl'Grordcn Clifford, Palowlto, cam; arid Ed: 1 Ward 'Rawlishen, deceased, *late ofi New'iYork, N .'iY., by: J Ohni'P3Wli5h8l'l, =ddministratorj New :York, 'Y.; assignors to: WestinghouseiElectric -i-Corporation,z' :East Pittsbuxgh;rBa;,-ia-wopporationofi Bennsylvania i it t Applicatiori December 30,:1942,"Se'rial'-No."470582 I =9mClaims. (01:: sis-r) This invention relates to ultra-highlfreq-uency slugs-l intoire entrant 558215. Cavity :Tesonators devices.andrsgenerators: for .electricityrz'oftultra- ;;;wholly.=-;enclosed'ain vacuum "may -bei't by high frequency,Qandmorev particularly tozsuch ztheizmal means, either byvexpansioni50f :aithin 'having' tunable resonant cavities enclosed-win wwal-led pieceibfrtubingsor::bysfilaments ,working evacuated envelopes. N5 sagainsasprings. :Gertainzdifficulties, however; are

.i'llhe principalwobject of thecinvention, generinherentzin-bo'th obthesemethods;although they tally considered, is to provide;ant-electronic;devtwill. function. .vie comprising anevacuated envelope tenclossinconsideringt. the possibility;ofmsingbimetaling a cavity resonator associated withoth'eneleeliccelementsutor:accomplish:tuning,wit-wasafound ments forefiecting theidesired -result, said reson-M ve y difficult to obtain a bimetallictstripf a n ator having a; flexible wall, temperature-respon- -two:necessamjqualifications; firstpsufficientwidth sive means in said envelope for adjustin the zxand thiclmesszato:zhavetmechanicalarigidity and position of said --wall1'tot tune theresonator;.:means --second,q suflicientw electricala resistivity t 430 give -.a to efiectaheatingJ-dischargex id temperaturevolteampere characteristic .in a: range :oonsistent responsive means, andmeans i'or controllinglthe i lfi witlnzpractical:application. a A-.filament-;may,tbe intensity of. said discharge in :order to properly cemployed stotheat the bimetallic. strip; :butthermal tune the resonator. i zdelayea-nd'cther disadvantagestmakeethis,unde- Another xobject ,-ofthe invention .jiS to; provide s mble.

. for the tuning of resonant cavities in theeevacu- Inaccordancawwith the =invention,=we-effect the .at d envelopes 0f ultra-high; frequency gener-XQOadesiied tumng-rofta cavity resonator any-evacuators bymeans avoiding timedelay-and possiblity =ated envelope: by mp oy ng b and of leaks. making it the anode of a small triode. ":Such tri- :A further object of. the invention. is to-provide coda-includes!325011168, fi t sflw ay be a device ior:. generating-electricity.of.ultraehigh r.a;filamentlofuanyssuitablex'materialcor an :indifrequency, consisting of an evacuatedaenvelope125 irectlyoheatedlcathode. Between this-sourceand enclosing a main cathode, .a.,cavi ty resonator the bimetalliciielement, tunctioning-as-an anode,

vthrm ghwhich an electronstreamt from; said main his:aggridastruotureecontrollingv:the :fiow; ofcelectcathode may pass, bin1eta11ic .mea,ns,fgr,,movjng ,etrons f-rom.thevsource:ofieelectronstorthe bimetala flexible wall of ,said resonator to tune the c- -e e entsame, and means for efiecting aninde endent, e =13yvirtue:ofthisconstructiom-we 'provideheat- V accuratelyecontrollable,,discharge .to: said'. bimeingp wer due toflelectrontbombardme e y .tallic means to accurately positionsaid flexible lthe de ce w ll respond more rap ly h F 1 wall to eifecttuning. r v Hheatedtbyradiation .fromma. filament andvefiect Other obj ects. and advantages of the invention, v control; .by'la r negative, grid which requires .Jsubrelating to theparticular arrangementcand constantiallmno power. We? thuswsimplifyccontrol struction of the various parts willbecometapparmircuitsexternaltothetube butwrequiredr-for its entt as the description proceeds. ..,operation.

Referring tothedraWings illustrating the in- Now referring to the drawingsin. detail,v.the vention: t reference numeral I lvtdesignates: an. evacuated Fig. 1 .is a fragmentary.axialsectionalview-ch40 envelope may be-zgenerally cylindrical and an electron device for generating.electricityflof l.mddiromanapp p c s s ultra-high frequency and invol-vingloneoembodi- .The tenvelopelis rigidwthroughoutland ..does not ment of the invention. .nedsto have-anylmoving-.parts projectingt there- Fig. 2 is a fragmentary axial sectional viewon through in order to embody thevention. ead- .thelineIIII ofjEig. 1,. in. the. directionwo fvlthe incon'ductors.orielementsnlZareshownformak- .arrows. lingtthe. desired connections. tTwotof theseele- Fig. 3 is a wiring idiagramiforlthev apparatus ..mentsvconnecttwitmanincandescible, filament 13 of Figs. 1 and 2. I Lfon heatinghan.associatedcathodel4 to electron- The use of -a cavity. resonatorsastanhintegral -.-emittingwtemperature. Theccathodedhhas its part of. an. electronic clevicev brought about.,cer- 5 ,vupperaors. active isi rface desirably wcoated iwith tain problems. in connection withltuningsuchta electron ir -emission .material, 7 such @25 alkaline resonator .by change of its :physical: dimensions, earths.

when in 'the'evacuated vdevice. tEarlymethods in- The structure which surroundsrthevfilament l3 volved the use: of rflexibleldiaphragms. Later, =an dlcathodetl4amaydbe -of:ygeneratlyconventional tuning was efiectedmby theinsertion. of tmetallice': 55. constructiontand :carried; .by t-thelowereor baseadjacent wall 15 of a cavity resonator l6 which wall is in turn carried by support members I! and I8, of nickel or other desirable material, enclosed in ceramic insulating cylinders I9 and 2|, and carried by a pair of lead-in conductors l2. The upper or opposite wall of the cavity resonator l6, consists of a resilient metal plate 22 which may be generally annular in plan and carry concentric corrugations 23 for increasing its efiective flexibility. The central portion of the plate 2.2 is connected to a hollow yoke structure 24 which is in turn connected through a strut 25 to approximately the center of a bimetallic plate 26. One edge of the plate is mounted, as by welding on a channel member 21, the latter in turn carried by a rigid cross brace 28 extending between and supported on the ceramic members I9 and 2 I.

In operation, a beam of electrons is directed axially of the envelope from the cathode 14, through a grid 29 carried by the cathode structure, a grid 3! carried by an upstanding or axially ,directed flange defining an opening in the lower wall l of the cavity resonator l6, and a grid 32 carried by the upper or flexible wall 22 of the resonator and spanning the central opening in the yoke structure 24, after which said electrons engage and are reflected back from a member 33. The reflector 33 is mounted on a transverse bracing structure 3A, supported by the ceramic members it and 2|. 1

From the above, the construction will be recognized as a hollow body resonant micro-wave generator of the reflex type, called a reflex klystron, wherein the upward or forwardly moving electrons are bunched in passing through the constriction between the grids 3! and 32, giving up'energy while passing back therethrough in bunches on the reflected or return path. Tuning of the resonant chamber I6 may, therefore, be obtained by changing .the spacing between the grids 3i and 32 and the distance between the walls I5 and 22. Y

To make such a change we provide a means for heating the bimetallic element 26 to cause the same to flex down, or toward themain cathode I 4, from the position shown in full lines to that shown in dotted lines, to thereby move the flexible wall 22 and its associated grid 32 closer to the lower or base-adjacent wall I5 defining the cavity resonator 16. Such action lowers the generated frequency, as will be understood by those skilled in the art. It will also be understood that such devices may be constructed so that when the bimetallic element 26 is at room temperature, the frequency generated may be a little higherthan that desired. The frequency desired may then be produced by heating the bimetallic element 26 to the necessary extent. I

Mounted above the bimetallic element 26, or on the other side from the cathode i4, is a control cathode 35 which may be an incandescible filament or indirectly heated electron emissive surface, the ends of which are supported by the insulating cylinders l9 and 2!. In the present embodiment we have shown a helical coil 36 surrounding the cathode 35 so as to control the electronic stream between it and the bimetallic element 26. This, however, is not essential, as a grid disposed entirely between the cathode 35 and bimetallic element .26 may be employed. This grid 36 is shown supported by a wire 3! the ends of whichare respectively secured to the insulating cylinders 59 and 2|.

The mode of operating the generator of Figs. 1 and 2 will be apparent from the wiring diagram 4 of Fig. 3. The reference character 38 represents a transformer, the primary winding 39 of which is supplied from a suitable source of power which .maybe 60 cycle alternating current. The secon'dary winding 4| supplies power to the cathode heating filament l3, as well as by the

shunt wires

32 and 43 to the heating means of auxiliary or control cathode 35. The cavity resonator includingthe

walls

15 and 22 is maintained at a positive potential with respect to the cathode M, as represented by thebattery 44, while the reflector 33 is made negative with respect to said cathode M, as represented. by the battery 45. The bimetallic element 26 is shown maintained at the same potential as the walls of the resonant chamber I6 by electrical connection 46 and the potential of the control grid 36 is manually variable, being governed by moving a pointer 41 of a rheostat or voltage divider t8, the ends of which are connected across a source of direct current such as battery 49.

It'will, therefore, be seenthat by making the voltage of the control grid 36 more or less negative with respect to the electron-emitting auxiliary cathode 35, the dischargeof electrons therefrom to heat the bimetallic element 26 to the desired temperature, may be accurately controlled. Thus the position of the flexible wall 22 and its associated grid 32 may be adjusted to make the frequency of the generated electricity that desired,-within the limits allowed by the structure. 1

From the foregoing, it will be seen that there is provided an electron device for generating ultrahigh frequency-in which all the essential parts are. enclosed in an evacuated envelope, even including thebimetallic means for tuning the resonant-cavity by changing the'physical dimensions thereof and the spacing'of the grids associated therewith. It will be noted that only one extra base pin or terminal is required, that is for the grid 36, since the control cathode may be operated in parallel with the main cathode and the bimetallic element directly connected to the resonant chamber. y

Although a'preferred embodiment of the invention has-been disclosed, it will be understood that modifications may be made within the spirit and scopeof the appended claims.

Weclaim:

1. An ultra-high frequency generator of the reflex klystron type, comprising an evacuated envelope, a main electron-emissive cathode, a cavity resonator through whichsaid cathode may discharge a beam of electrons, a reflector electrode at the opposite side of the resonator from said cathode support means for said members, one of the walls of said resonator through which said beam passes being flexible, a bimetallic plate with one end rigidly secured to said support means, a structure straddling said reflector electrode and connecting a portion of said bimetallic plate which is spaced from its secured end to the flexible wall, a control cathode disposed adjacent ply source adapted to be manually varied in poegeaeoa trol cathode and bimetallic plate,-and'by virtue of the corresponding movement ofsai'd element upon changing its temperature, adjustably position said flexible wall to effect a desired tuning of said device.

2. An ultra-high frequencydevice comprising a main electron-emissive cathode, a cavity resonator adjacent thereto, bi-metallic means having one end fixed with respect to the device, allowing the remainder to have flexing movement to and from said resonator, means connecting a movable portion of said bimetallic means to said resonator, a control cathode disposed adjacent said bimetallic means, a grid disposed between said control cathode and said bimetallic means, potential-source means coupled to said bimetallic means and control cathode for making said bimetallic means function as an anode for said controlcatho'de, an envelope enclosing :all of said elements, connections from said control cathode to a source of current for efiecting an electron discharge from said control cathode through said grid to said bimetallic means to heat the same to a desired temperature, a manually-variable electrical supply source, and connections thereto from said control cathode and grid for regulating the potential of the latter to control said electron discharge therethrough and the corresponding heat eifect on the bimetallic means to adjustablydistort said cavity resonator and effect a desired tuning.

3. An ultra-high frequency device comprising a main electron-emissive cathode, a cavity resonator adjacent thereto, a wall of said resonator being flexible, bimetallic means having one end fixed with respect to the device, allowing the remainder to have flexing movement to and from said resonator, means connecting a movable portion of said bimetallic means to said flexible wall, a control cathode disposed adjacent said himetallic means at a side thereof opposite the main electron-emissive cathode, a grid disposed between said controlcathode and said bimetallic means, potential-source means coupled to said bimetallic means and control cathode for making said bimetallic means function as an anode for said control cathode, an envelope enclosing all of said elements, connections from said control cathode to a source of current for effecting an electron discharge from said control oath-ode through said grid to said bimetallic means to heat the same to a desired temperature, a manually-variable electrical supply source, and connections thereto from said control cathode and grid for regulating the potential of the latter to control said electron discharge therethrough and the corresponding heat effect on the bimetallic means to adjustably position said flexible wall and effect a desired tuning.

4. An ultra-high frequency device comprising an evacuated envelope, a main electron-emissive cathode, a cavity resonator adjacent said cathode in said envelope, said resonator having a flexible wall, a bimetallic plate having one end fixed in said envelope so that upon heating, the remainder will flex toward said resonator, means connecting an intermediate portion of said plate to said flexible wall, a control cathode in said envelope adjacent said plate and disposed remote from said main cathode, a grid between said control cathode and plate, potentialsource means coupled to said plate and control cathode for making said plate function as an anode for said control cathode, connections from said control cathode to a source of current for effecting electron discharge from said control cathode-through said grid to said plate, a manually-variable electrical supply source, and connectionsthereto from said control cathode and grid for regulating the potential of the latter to control said electron discharge therethrough and the consequent heating of said bimetallic plate to adjustably position said flexible wall and effect a desired tuning.

'5. A discharge device comprising an evacuated envelope enclosing a main cathode, a cavity resonator through which an electron stream from said main cathode may pass, one of the Walls of said resonator being distortable, bimetallic means operably connected to said distortable "Wall, a control cathode, a grid therefor, potential-source means coupled to said bimetallic means and control cathode for making said bimetallic means function as an anode for said control cathode, connections from said control cathode to a-source of current for efiecting an independent discharge to said bimetallic means to quickly heat it to a desired extent, a manually-variable electrical supply source, and connections thereto from said control cathode and grid to control said independent discharge to vary the heating ofthe bimetallic element and thereby the physical dimensions thereof to accurately position said distortable wall and effect tuning of the resonator.

6. A tuning device for an electron-discharge element through which a discharge may pass from a main electron source in an evacuated envelope, comprising temperature-responsive means enclosed therein and attached to said element, a control cathode, a grid therefor, potential-source means coupled to said temperature-responsive means and control cathode for making said temperature-responsive means function as an anode for said control cathode, connections from said control cathode to a source of current for effecting an independent electron discharge to said temperature-responsive means, a manually-variable electrical supply source, and connections thereto from said control cathode and grid to vary the heating of the temperature-responsive means and thereby its physical dimensions to vary the physical dimensions of said element and effect a desired tuning.

7. A discharge device comprising an evacuated envelope, a main electron source therein, and a tuning device for an element through which a discharge may pass from said source, comprising bimetallic means attached to said element, a control cathode, a grid therefor, potentialsource means coupled to said bimetallic means and control cathode for making said bimetallic means function as an anode for said control cathode, connections from said control cathode to a source of current for effecting an independent electron discharge to said bimetallic means, a manually-variable electrical supply source, and connections thereto from said control cathode and grid to vary the heating of said bimetallic means and thereby the physical dimensions thereof to vary the physical dimensions of said element and effect a desired tuning.

8. An ultra-high frequency device comprising a main electron source, a cavity resonator adjacent thereto, temperature-responsivemeans at tached to said resonator to vary physical dimensions thereof, a control cathode adjacent said temperature-responsive means, a grid for said control cathode, potential-source means coupled to said temperature-responsive means and control cathode for making said temperature-responsive means function as an anode for said control cathode, an envelope enclosing all of said elements, connections from said control cathode to a source of current exterior of said envelope for efiecting an electron discharge through said grid between said control cathode and temperature-responsive means, a manuallyvariable electrical supply source, and connections thereto from said control cathode and grid for regulating the potential of the latter to control the heating effect produced by said discharge and adjustably distort said resonator to efiect a desired tuning.

9. An ultra-high frequency device comprising a main electron source, a cavity resonator adjacent thereto, a wall of said resonator being flexible, temperature-responsive means connected to said flexible wall, a control cathode disposed adjacent said temperature-responsive means but relatively remote from said main electron source, a grid for said control cathode, potential-source means coupled to said temperature-responsive means and control cathode for making said temperature-responsive means function as an anode for said control cathode, an envelope enclosing all of said elements, connections from said control cathode to a source of current exterior of said envelope for effecting an electron discharge through said gridbetween said con trol cathode and temperature-responsive means, a manually-variable electrical supply source, and connections thereto from said control cathode and grid for regulating the potential of said grid to control the heating effect produced by said discharge and adjustably position said flex,- ible wall to effect a desired tuning.

DAVID GORDON CLIFFORD.

JOHN PAWLISHEN, Administrator of the Estate of Edward Pawlz'shen,

-- Deceased.

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

UNITED STATES PATENTS Great Britain June 25, 1941