US2774946A - Controller for wave guide tuner, phase shifter, or attenuator - Google Patents

Description

United States Patent 2,774,946 I CONTRdLLER FORv WAVE GUIDE TUNER, 7 PHASE SHIFTER, 'OR ATTENUATOR Clare D McG-illem and Frank Hasseld, Jr.,v indiana olis,.Ind., assignors to the United States of- America as're resented'by the Secretary of the Navy Application March 12, 1954,- S'erial'No. 415,987

Claims. (Cl. 333-98) Grantediunder Title 35,. U. 5. Code 1952), sec.-266) The invention described'herein may be manufactured andused by enter the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This inventionrelates to waveguidesand more particularly to a meansfor controlling a.conductive impedance element or a dielectric impedance. element within a rec'- tangular. waveguide from a point. externally thereof in a compact: manner to-contr0l the microwave energy therein without producing any openings, cavities, or extensions within the waveguideto otherwise deteriorate from o contaminate the microwave energy. V

In the known tuner, attenuator, and phase shifter controlling devices for waveguides, the controlling mechanism is a rather cumbersome piece of' equipment supported externally of'the waveguide. In some of these devices one of the faces of the waveguide is slotted along the center and the internal element is mechanically raised or lowered? into and out of the waveguide through the. slot; Other means of. single screw, single slug, or multiple screw or slug controlling. devices are commonly used wherein variations in the depth of the screws or slugs, or of the spacing of multiple screws or slugs, provide the control at" the sacrifice of cumbersome external manipul'ating means. Further; waveguide openings or cavities for these screw or slugjmea'ns often: produce undesirable modification in-the microwave energy. The above known devices are usually madewith coarse adjustment means and" oftentimes donot provide a smooth operation for control over the microwave energy which is necessary'in precision use ofthecontrolling'elements.

In the present invention spaced circular openings are cut through oneface of'a rectangular waveguide near a corner thereof. A pair of disk-s arerotatably mounted inl'the'se circular openings and are coupled t'og'eth'ento rotate: in unison". The innersurface of each-disk is flush with the inner wall of the waveguide and each dish is eccentrically pivotally: connected on=itsinner face to an elongated planan' impedance or microwave control" element, .the pivotal: points on th'e respective dish'slyingin'the" same relative eccentriclposition whereby the' unitar y rota tion of the disks carries the microwave control element to and from thexcentral; area of. the waveguide.- The microwave controlelen'ient is tapered on eachend toa halfi wave length in the: usual'rand ordinary manner of: construction ofi these elements. It: the device of themes: ent invention is used as a tuner, the materialof'the niicrowave controlelement: should be at good electrical conductor. If thedevice is used as an attenuator of'tli'e microwaves, the material of themicrowave: cont'rol' ele ment should be of.a lossy material, as carbon. Poly styrene has been found to be the best material for'constructing the microwave control element where the device is to be used to phase'shi ft the microwaveenergyalthough most of the dielectric materialshaving a high dielectric constant may be used, where desired. It is therefore a general. object of this invention to provide a. compact manipulating'means for controlling'th'e microwave energy inra rectangular waveguide without making any obstructions or openings therein to contaminate or deteriorate from the microwave energy.

These and other 'ohjects; advantages, features, and uses will become more apparent as: the description proceeds 2,774,946 Patented Dec. 18, 1956.

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2" when considered with the accompanying drawing, in which:

Fig. 1. is a top elevational'partial view of a waveguide showing. the external. adjustable means of the impedance element in accordance with this invention;

Fig. 2 is a view similar to Fig. 1 showing the impedance element in a diiferent'adjustedposition;

Fig. 3 is a side longitudinal cross-sectional view taken along'theline 3'3'o'f Fig. 1;

Fig. 4 is a side longitudinal cross-sectional view taken along'theline 44 ofFig'. 1;

Fig. 5 is a partial top'viewof the device shown in Fig. 1 showing an additional meansv to drive the adjustable means;

Fig. 6 is a top plan view of a modified form of the adjustingmeans shown in Figs. 1 and 2; and

Fig. 7- is a top plan view of still another modification of the impedance element'adjusting' means.

Referring more particularly to Figs. 1 to 4, there is showna=rectangular waveguide 10 on one face of which is supported an adjustable means for an internal microwave control element. Two circular openings 11 and 12' rotatably support two-similar shouldered gears 13 and 14, the shoulders 15 and. 16; respectively, of each resting against the outer surface of the waveguide 10 with the inner face of each being flush with the inner surface of the waveguide. The two- gears 13 and 14 are held against movement outwardly from the openings 11 and 12 by a retaining bracket 17 having the outermost ends 18 and 19 tur'ned' at: right angles and pivotally set respectively in central sockets- 20'a nd 2 1 of gears 13' and 14. The retaining bracket 11 isheld in position by a studscrew 2i2 'threaded in a' tapped opening ofthe waveguide equidi'stantly between the two gears 13" and 14. The stud 22'- is shouldered at the en'd'of the threaded portion to-h'o'ld the' retaining bar 17 i111 a: predeterminedpos'ition. Qn'the shank of the screw 22 b'etweenthe retaining bracket 17 and the wall of the. waveguide 10 is an idler gear 23 that meshes with both gears 13" and 14-. The idler gear-23 couples the gear-s'1'3-and'14 together to cause simultaneous rotation of these-two gears i'n'the same rotative direc= tion' and'at the same angular. speed;

Each. of the gears 13 and-1'4' has a drilled opening ec centrically therethrough in each'of which 'is fixed; as-Iby' cementing orpress'fitt'ing, a dielectric rodor pin 301 and" 31,.respectively,'moreclearlyseen in Fig; 3'. Each rod is positioned at the same radial distanceonu the respective: gear and in the same angular relation. so; that they will movev in equal amounts over identical arcs fromtheside wallofthe waveguide upon actuation of the gears 13 and 14:. In ordento-arrange-the-ro'ds 30 and'31-to'operate between positionsadjac'ent the side: wall. of the Waveguide and the central area: thereon-the openings and 12 are made near one corner of thewaVeg'uide as shown! The rods 30-and 3l extend intorblin'd-bo'res. 32 and 33; respec tively, of athinlmic'rowavecont'rol:element 34, best seem inFig:v 3. The element 34is-a thi-nastrip 'ofirnaterialithat: is slightly narrowerthanthe Waveguide ifinensideWalldi-fmensionto perm-it- -it= to be A sl-idably-oarried' by the r rodsr30? and 31 laterally back and forth across the: Waveguide from: the waveguide sidewall.- to the central. area; as: seen in Fig. 2. The sidefaces of. the. element- 3.4-alwaysremainparallel tothe sidewalls-of the waveguide-such that. in the position where the element 34is fully withdrawn from the= centrallarea of the waveguideit isheld fiat againsttheside: wall 'and is' substantially ineffective on. the microwave. energy. Theeler'nent 3'4is shownas a dielectric material such as polystyrene for the purpose. of illustrating theinventio'n althou h conductive material or earbonous material may be" used where the device to fun 'on as a tuner or an at'tenuator, respectively. The'endsotthe Inent snare our at an angleferminga paraueleg'ram' the sides, as viewed in Figs. 3 and 4, as is the usual practice in controlling the phase of the microwaves, these tapered portions being in the order of one half a wavelength of the microwaves for optimum matching.

The teeth on the gears 13 and 14 serve as knurled portions for manually. manipulating the adjustment of the microwave control element 34, the actuation of either gear producing the adjustment. It may be desirable in some instances to actuate the adjustable means by a motordriven means to produce cycling, or the like. In such instances a worm gear 36, as seen in Fig. 5, may be meshed with the gear teeth of one of the gears 13 or 14 and rotated through an integral or fixed shaft 37. The worm gear 36 and shaft 37 are supported in bearing supports 38 and 39 attached to the waveguide.

The two gears 13 and 14 may be replaced by pulleys 40 and 41, as shown in Fig. 6. The pulleys are coupled together by a belt 42 whereby the pulleys rotate in unison to carry the microwave control element 34 laterally back and forth in the waveguide. A driving or cycling means may be coupled to one of the pulleys in the same manner as shown in Fig. 5.

As shown in Fig. 7, the gears 13 and 14 may be replaced by sprocket wheels 45 and 46 and coupled together by a chain 47. The rim of one or both of the sprocket wheels could be toothed to provide knurled means for manual adjustment or to couple a driving or cycling means as shown in Fig. 5.

The operation of the waveguide controlling device is believed to be clear and apparent from the above description but a brief description of operation will be given herein for the convenience of reference. For an example in describing the operation, let it be assumed that the device is a phase shifter wherein the microwave control element 34 should be made of a dielectric material as polystyrene. In the position shown in Fig. 1 the control element 34 is adjacent the side wall of the waveguide where substantially no phase shift is produced. By rotating either gear 13 or 14 in either rotative direction the control element 34 will be carried in an increasing amount toward the center of the waveguide or the extreme position, as shown in dotted lines in Fig. 2. The shift in phase of the microwaves passing through the waveguide is a continuously increasing function as the distance of the control element 34 is increased from the sidewall to the center, the maximum occurring when the control elemeat 34 is positioned in the central area of the waveguide. The inner faces of the gears 13 and 14 provide a smooth continuation of the inner wall surface of the waveguide so that the microwave energy is not altered in any way by the actuating mechanism.

Tuning can be accomplished in the same way where the microwave control element is of good electrical conductive material. Attenuation of the microwaves in the waveguide may likewise be adjustably controlled by using a lossy material as carbon, or the like.

While the preferred forms of the invention have been shown and described herein, it is to be understood that many modifications and changes may be made in the constructional details and features of this invention without departing from the spirit and scope thereof and we desire to be limited only in the scope of the appended claims.

We claim:

1. In a waveguide a means for controlling the microwave energy therein comprising, a pair of circular openings through a wall of the Waveguide in longitudinal relation, a pair of circular elements rotatably journaled in said circular openings respectively with the inner face of each flush with the inner surface of said waveguide and being coupled to rotate in unison, and an elongated microwave control element in said waveguide and lying longitudinally thereof, said control element being pivotally associated with said pair of circular elements at separate points whereby rotation of either circular element of said pair will shift said control element laterally in said waveguide.

2. In a rectangular waveguide a means for controlhng the microwaves therein comprising; a pair of circular openings through one wall of the waveguide in longitudinal relation thereof; a pair of circular elements, one each being rotatably journaled in one each of said circular openings with the inner face of each flush with the inner surface of said waveguide; means coupling said pair of circular elements for rotation thereof in unison; an elongated microwave control element within said waveguide lying longitudinally thereof; pivotal means connecting each circular element to said control element at spaced points; and means for rotating at least one of said circular elements of said pair whereby rotation of said one of said pair of said circular elements will shift said control element laterally of said waveguide.

3. A device as set forth in claim 2 wherein said circular openings are, of a diameter equal to substantially one-half the internal width of said waveguide and a sidewall of said waveguide is tangential to said circular openings, and said pivotal means is a rod extension on each circular element eccentrically and parallel to the axis of each respective circular element each extending into a bore in said control element.

4. A device as set forth in claim 3 wherein said means for rotating at least one of said circular elements are gear teeth on the periphery of said one element extending above and externally of said waveguide.

5. A device as set forth in claim 4 wherein said means coupling said pair of circular elements for rotation in unison are gear teeth on the other of said circular elements extending above and externally of said waveguide and an idler gear meshing with the gear teeth of both said circular elements.

6. The device as set forth in claim 2 wherein said means coupling said pair of circular elements for rotation in unison is an idler gear between said circular elements cooperative with gear teeth on the periphery of said circular elements and said means for rotating at least one of said circular elements of said pair is a worm gear in mesh therewith, said worm gear having a shaft extension thereon for transmitting power from a rotational source.

7. A waveguide control device as set forth in claim 2 wherein said means coupling said pair of circular elements for rotation in unison is a belt passed over pulley portions of each circular element exterior of said wave guide.

8. A waveguide control device as set forth in claim 7 wherein said means for rotating at least one of said circular elements of said pair is a worm gear on a power input shaft in mesh with gear teeth on said one circular element.

9. A waveguide control device as set forth in claim 2 wherein said means coupling said pair of circular elements for rotation in unison is a chain passed over sprocket portions of each circular element exterior of said waveguide.

10. A waveguide control device as set forth in claim 9 wherein said means for rotating at least one of said circular elements of said pair is a worm gear on a power input shaft in mesh with gear teeth on said one circular element.

References Cited in the file of this patent UNITED STATES PATENTS 168,575 McCloskey Oct. 11, 1875 2,560,685 Cooper July 17, 1951 2,596,113 Allebach May 13, 1952 2,602,893 Ratliff July 8, 1952 2,634,332 Zaleski Apr. 7, 1953 FOREIGN PATENTS 681,801 Great Britain Oct. 29, 1952

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