US2531454A - Directive antenna structure - Google Patents

Description

Nov. 28, 1950 R. J. MARSHALL DIRECTIVE ANTENNA STRUCTURE Filed Feb. 4, 1942 Patented Nov. 28, 1950 2,531,454 DIRECT-IVE ANTENNA sTaUc'r-URn Ro rt Marsha l E rst N- I? sne ry"Canad an a mp assignor to """of Dela;

Application February 4, 1942, Serial No. 42949.4 1 Giaims; 259135-65) T ion re a s e era to he irectionaljreception ortran'smission of high frequency electromagnetic energy and the invention more particularly relates to a novel directive ail; tenn'a structurehaving a series of, diifering zones or," peated in regular sequence.

"Heretofore, directive antenna means have been employed for setting upa series 0t directed zones of. transmission or] reception, such antenna means comprisinga'radiating antenna and a cooperating" QQel'itricaHy mounted parabolic or other reflector; such reflector'being rotated to produce the desired space pattern. The rotation of these refl t f hi h s ed s ndes a e o g o. the windage and to gyroscopic effects. Furthermore," such reflectors are usually supported in large diameter bearings where a wave guide is used. to convey the energy to or. from the antenn'a means, such large bearings having, but a slhoirtj'life in use an tending to. cause overheating and excessivewe'ar" of the relatively movable pa ts.

"One object of thepresent invention is to. pro:

videfa novel directiveantenna structure adapted injuse to establish a series of overlapping zones of] electromagnetic radiation or reception, said series being repeated indefinitely.

Another object of the present invention is to provide a novel antenna structure comprising a reflector and wave guide means for supplying electromagnetic radiation to said reflector for receiving,radiation therefrom.

Still another obje btfof thei presentinvention is tofprovide a novel directive antenna structure comprising. a fixed. reflector wave guide means for conveying energy to orrfrom said reflector,

and motpndriven deflectin means cooperating.

with the mouth of saidwavel'guidefor producing a, lobe of electromagnetic radiation or reception whosecentral axis continuously revolves defining the surface of revolution of acme, the apexor such-,"surface being centered at the. antenna structure."

Other objects and. cadvantagesvwill become ap parent" from the specification, taken inlconnection, with the. accompanying drawing wherein the invention is embodied in concrete form,

15 the drawings,

Fig. 1 is a sectional view oftan antennalstructure embodyingthe principles of the present invention.

2 jis a detailed view showing a somewhat;

cfeption or transmission; said series being recone. On the other hand, if the antenna struc 2" sections oi the received or transmitted lobeslof' electromagnetic energy.

Fig. 5 is a View similar to Fig. 1 but of a, some! what modified structure.

Fig. 6 is a detailed cross section of a, modification of the structure ojEig; 5.

lfig, 7 is a fragmentary sectional View of a slight modification of Fig. 1.

Similar characters of reference are used: in all; of the above figures to indicate; Corresponding parts.

Referring now to Fig. 1 of the drawings; areflector l as of'the parabolic typeis shown mount-.- ed; on the end portion of a wave guide 2.", which in turn feeds into. or is fedfrom a concentric line 3 4. Theinner conductor 3- of, theconcem, tric line .3, it, is shown extending into astubiguide. 5 havinga movable plug 6 therein formatchin the impedance ofline 3 4 to guide 2. A plunger 1 having a handle 8 is also movable in the end. portion of guide 2 for aiding in this adjustment. The discharge end of wave guide 2* within reflector l is shown surrounded by deflectormem-t her. or nozzle H preferably having the fcirmof the wave guide section and extending at an angle. to the guide 2, the deflecting member It being provided withan annular. flange or sleevedoverlyingt he end portion of guide 2 but preferably: not contacting this uide. The deflecting menu-L ber. H is carried by arms I2 preferably of dielecrtrio material that are attached to a circular plate I3 which in turn is mounted to be rotated or.- otherwise moved upon the endof a motorishaft,

M which is driven by a motor l5. Thus, where the antenna structure is used asa radiator enorgy, leaving guideZ is directed'by, deflector ll so as to strike plate l3 at an angle. to the per.- pendicular andisreflected from this plate back against the reflector l and then; projected sub-e stantially as a lobe such a the lobe llshownin Figs, 3 and 4. Nozzle H and platetl3 thus: serve as deflection means for conveying energy between, guide 2; and reflector l. As'motor sha ftnltrem volves, this lobe. also, revolves, its longitudinal ic axisdescribing the surface of; a right circulalt ture is used as a receiver it will havea revolving; zone of electromagnetic reception which inany instance will have the form as shown at l1 but which will revolve as indicated in Figs. 3 andg ii The motor I5 is shown supported by arms I5; which preferably are of dielectric material con-t nected at their outer endsto reflector; l or othen; suppo t di ms: Q-heln reducetthegyrosqopictwtioa of revolving plate IS the structure of Fig. 1 may be modified as in Fig. 2, if desired, wherein the reflecting plate 20 corresponding to plate l3 of Fig. 1 is formed in two parts, an outer annular part l9 carried by struts 22 attached to arms 16 and an inner circular portion 2! that is rotated by motor 15 and which carries the arms l2 supporting the deflector member i I. The action here is similar to that in Fig. 1' except that only a small portion of the reflector disc 20 revolves, namely, the portion 2 i.

In Fig. the deflector member is shown in the form of an inclined disc 23 positioned in front of the mouth of guide 2. Energy discharged by guide 2 is deflected by disc 23 to one side and against the inner surface of reflector l and as the disc 23 revolves this energy is directed progressively against different portions of the reflector l to produce the revolving lobe of electromagnetic energy shown in Fig. 3. Likewise, if the structure of Fig. 5 is used as a receiving antenna its zone of sensitivity will revolve as shown in Fig. 3 due to the rotation of the deflector 23.

Owing to the fact that the deflector 23 is inclined with respect to its axis of rotation this deflector tends to produce more or less windage and vibration which can be reduced by encompassing this deflector in an insulating cylinde having portions 26 and 26 at opposite sides of the disc 23' as shown in Fig. 6. The action of the structure in Fig. 6 is similar to that of Fig. 5'.

In Fig. '7 a slight modification of the structure of Fig. 1 is shown wherein the plate 13 is shown in the form of a semispherical dislr instead of the flat disk [3 shown in Fig. l, the disk l3 also being inclined as illustrated. The action, however, is quite similar to the structure of Fig. 1.

As many changes could be made in the above construction and many apparent widely diflerent embodiments of this invention could be made Without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A directive antenna system comprising, a stationary reflector, a wave guide extending through said reflector and communicating therewith, a deflector member comprising a wave guide portion cooperating with the mouth of said wave guide and extending at an acute angle thereto, and a rotatable plate positioned in front of said deflector member and connected for rotating the latter therewith.

3. A high frequency directive antenna system comprising, a parabolic reflector, a wave guide projecting through said reflector substantially concentrically with the axis thereof, a deflector plate positioned in front of the mouth of said Wave guide and inclined at an acute angle relative to said guide, and means for rotating said deflector plate to render said antenna structure successively sensitive to diiiering zones of electromagnetic reception, said inclined deflector plate being contained within an insulating cylinder that is symmetrical with respect to the axis of rotation of said plate.

3. In a directive antenna having a paraboloidal reflector, and a wave guide emptying into the cavity formed by said paraboloidal reflector, the combination comprising a deflector mounted asymmetrically relative to an axis of rotation and operative when rotated to deflect electromagnetic waves from said guide onto successive 4 portions of said reflector, and dielectric means filling out the asymmetrical portions of said deflector to a form symmetrical about said axis.

4. In a directive antenna structure having a substantially parabolic reflector, and a wave guide extending substantially coaxially with said reflector, the combination comprising an eccentric nozzle member adapted to deflect electromagnetic waves issuing from the end of said guide, and means for rotating said member relative to said reflector.

5. The combination as claimed in claim 4 wherein said nozzle member includes a sleeve portion surrounding but rotatable relative to said end of said guide.

6. A directive antenna structure having a substantially parabolic reflector, an electromagnetic wave conductor extending through said reflector substantially coaxially with said reflector, means including a movable deflector having a major portion within the concavity of said reflector eccentrically disposed relative to the axis of said reflector for directing waves from said conductor onto a portion of said reflector, and power means disposed on the side of said deflector opposite said conductor for moving said deflector relative to said reflector to direct said waves onto successive portions of said reflector.

'7. In a directive antenna structure having a substantially parabolic reflector and an electromagnetic wave conductor adapted to radiate energy into the cavity formed by said reflector, the combination comprising a support extending across said cavity, a deflector adapted to reflect radiant energy onto said parabolic reflector, and power means on said support adapted to move said deflector reiatively to said parabolic reflector.

8. The combination as claimed in claim 7, wherein said deflector comprises an eccentric nozzle for said radiant energy rotatable relative to said reflector.

9. The combination as claimed in claim 7, wherein said deflector comprises an eccentric nozzle for said radiant energy rotatable relative to said conductor, and a convex deflector plate rotatable relative to said reflector for diverting radiant energy onto successive portions of said reflector.

10. A directive antenna system comprising a concave reflector, an electromagnetic energy conductor fixed thereto and extending through said reflector, means at least partially within the concavity of said reflector for interchanging energy between said conductor and a portion of said reflector, and means for moving said. inte changing means to cause said reflector portion to change successively, whereby the directivity characteristic of said system is varied.

11. A system as in claim 10, wherein said interchanging means comprises a deflector memher for changing the directivity characteristic of said energy interchange, and wherein said moving means comprises means for rotating said deflector member relative to said reflector.

12. Apparatus as in claim 10, wherein said intween said reflector and'said conductor, and

power means mounted on said support for moving said deflector means relative to said reflector whereby the directivity characteristic of said system is varied.

14. A directive antenna comprising a reflector, a Wave guide projecting through said reflector and fixed thereto, a wave guide section communicating with said first guide and in non-alignment with respect thereto, and means for mov ing said section relative to said guide to vary the directivity characteristic of said system.

15. A directive antenna system comprising a reflector, an electromagnetic energy conductor fixed thereto and extending through said reflector, means for interchanging energy between said conductor and a portion of said reflector, and means for moving said interchanging means to cause said reflector portion to change successively, whereby the directivity characteristic of said system is varied, said interchanging means comprising a deflector member in the form of a section of electromagnetic energy conductor disposed in non-alignment with respect to said first conductor.

16. A directive antenna system comprising a reflector, an electromagnetic energy conductor fixed thereto and extending through said reflector, means for interchanging energy between said conductor and a portion of said reflector, and

means for moving said interchanging means to cause said reflector portion to change successively, whereby the directivity characteristic of said system is varied, said interchanging means comprising a convex deflecting plate positioned before an end of said conductor and maintained at an angle thereto.

17. In a directive antenna structure having a substantially parabolic reflector, a wave guide section having an open end and an axis acutely angularly disposed relative to the axis of said reflector, said wave guide section being rotatable REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,931,980 Clavier Oct. 24, 1933 2,083,242 Runge June 8, 1937 2,206,923 Southworth July 9, 1940 2,281,274 Dallenbach et al. Apr. 28, 1942 FOREIGN PATENTS Number Country Date 694,523 Great Britain July 4, 1940 370,135 Great Britain Apr. 7, 1932

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