US2605412A - Collinear sleeve type antenna array - Google Patents

Description

y 29, 1952 H. J. RlBLET COLLINEAR SLEEVE TYPE ANTENNA ARRAY 2 SHEETSSHEET 1 Filed Sept. 14, 1945 INVENTOR HENRY J.RIBYLETI I ML ATTORNEY y 29, 1952 H. J. RIBLET 2,605,412

COLLINEAR SLEEVE TYPE ANTENNA ARRAY Filed Sept. 14, 1945 2 SHEETSSHEET 2 FIG? HENRY J. RIBLET ATTORNEY Patented July 29, 1952 mosey:

E-ANT NNAA B Y Henry Riblet, Gambridge, Mass", assig-nor, by lnsne assignments, to the'United -S't ates- 01' America as: itemgesentedj by: the: Secretary of the New Mypresent invention'relates to radio antennas anqlsfin partieulan to a radio antenna e'oim misi-ngone or more tubular shaped radiators haying radiation: polarized in the-direction of the axis of"thesaigl ragiiatbrsa v My present invention contemplates a noveltype' of antenna element which; may be used singly or in arrays in any known and usual fashion Broadly, the invention-comprises mth oils and: meansfor: producing radiating current on the'sur'iaee of-a metallie tube: These-methods and? meansl are-hereinafter embodied in an an ten-nae having (substantiallyeylindrieal radiation tubes. whichaare of: the order: of: one-half aa-wa've length-1. long. However, it wil-1:.be=- understoodbythoseis'killed intheart thattthe lngth andfishape of these. tubes arevnothlimitmg, but-merely illustrative; and; thatamany other; lngthsand shapes will he; abletohe: used."

It is; accordingly; anxnobject of? my: invention n; pmyide. an antenna.v element comprising atv metallics tube having. radiating current": on. the outer surface thereof;v

It another objectof my inyentionto provide; a radiqlantenna comprising a pluralityzofisuch tubular antenna-i elementssarrangedt in. a fashion; adapted; to: produce: a; pancake; shapedv beam havin DQlarization. substantially perpendicular. ethe p ane of; the beam;

It 18,- a: iunth r- Qbjeet of my;-inventiontt 1pro-M ide: novel; feeding. and; supporting; means-alongqldin su h uhulan antenna: elements I on; aeqaxial or: wave gl1i(1& type .of; transmission: line;

lt siat t l iu t er-obieet of, my inventionzm eviqesuch a n ennaa raythat will be-simnle he; cp stmct n to ,aida'yst aria-tune Q 99; Qbie ts ndmatu es: of; invention will: 22 9 599- eranay ni pm a; care lonsiderr ationoithe f v T H1; .v l mime em ssl ments; 91 5 .118; nvention: v In li fl awina;

Fig. 1 illustrates an antenna:ofwmyginvention;

. Fi o ll s etesia novelsu qrting; meansafor .1 w ements inf-Fla: 1;

onera iq r :.the ante na ohms 1;

Ri -i 3; 2 illustrates lanxalternative; shape for; the; antenna -e1ement ofrthe:antenna;.ofaEig; ;1';

illustrates; an' antenna: of; myinvention arranged to; produce-a; pancake sshaped beam;

Figs, fijand 6;. arescross sectionsrof Fig; 4; taken alomg. thel'lines. V'V and!VI--VIi1:espectively.;- an s mgi-vsistzanuther antennaotamy mventlon-aam 18 a di rammatic; illustration sofa; the;

. 17:01am; (Cl. 250-8353) 6,5:- th'ezusualmannem 2 ranged for producing a: pancake shaped beam n Fig; 1 afirst cylindrical tube" 4 and'afs'eeend cylinglrieal tube 2 are arranged coaxial 1y and lihearlyagljacent to each other with their- -u tual-ly'dii eoted edges: 3 and 4- spaced a" small ciistance apart; Agjaxi a-l typetransmissi n -line 5} hayinghn outereondue'tor- =6 and an mnei ongiuotor =1 is disposed within'these tubes l'- and 2; being coaxialtherewith; supporting-spider 8, illustratedalso inFigijZi compi ising a' -collax Q 'and three 'p'airls of rst; and seoonri' fl nge'rs Ill and l l fespe c'tiyely-is adapte'gi'to'fit snugly ensue" outer eoniiuctor 6 of the coaxial-- 1 "e 52 "epaiis oifingers In and ll respectively -area a ianged to Slipp'prV the; two oylindr 1 tubes @lf anl' '2i ,respeetiyely: Inany-ba-ir o" ngers and; l lfthfe two members;-of 'said pair a e ar ranged axially with resueet to the eella 9} am therefore with respect to the-axis of the coaxial line'5. The ii'rsttulge I" supper-weapon the three fi'rst' members I0 of the pairs m nagers; whilethe second tube 2 "issupported upon seeondthreem'embers ll,--ofthepairs oi fig' The tubes I and Lniaybe joined to' the-fingers 0 nd l efi m el b f qw m an s as solden or 'bolting. Three holes l2--ai pie vidd the;coll' '9. each hOIe-heing disbosd between the'; meinbers |0-- and- It of a 'p I of fingers Similarholes l3 are p ovigied in t lieu outr wall 6 of -the wave-guigle 5 The p'aiis ef fingers lllfand- It; and the-holes ll-ancl Hire spe'ctively; arelsymmetrieally disposed" about thecircumferential surfaceof the oollar gan'd'i the outer con'duct o r 5;-

theseholes--and ge1gf offingers are-'suhsta-ntially 1 20? apa 'rti 'Ifiabs H are-piiovidedjon the inneredee'fi of thefii'stcylind'i iea ly cube 1 Thesetabs "m y e thre in-numben-and are preferably also sym etheany. dispeseq about the'eq'ge iia The firs't 'cyli'tid r i 1- tube is so disposed; u'pon the-first -thr' sup porting/fingers Ill-that atab lk'liesdii'eetlymvn a hole I2. The holes l2 and I3 a1 e-ali Ii'e "so that -a' paiyoff'holes I2 and Iiitogthe or passage into the wav'e guide- 5 throu" h over each ofxathese passages-. probe; l 5 I videci ineach tab lk;b'emg fiz inly inolihte m in anci therethrough' and extending into the wa sages? The-probes l5 terminat in 'the pacebetween: the: outerconductor 6- and the infier conductor: 1; Theseprobes I5 4aresuitably -iif thewform of v screws and may-"be adjustedas 1 theirzpenetration inte -the line. 5 by 'turnln'g in- The operation of the apparatus illustrated in Fig. 1 may best be understood with reference to the diagram of Fig. 2a, in which parts similar to parts of Fig. 1 are similarly numbered with the addition of the letter a. Thus a transmission line a comprising two conductors 6a and la has two supports. Illa and Ila upon one conductor Ba. -'Iwo radiating elements "Iaand 2a are supported upon these supports Illa and Na respectively. A passage P corresponding to that provided by two aligned openings I2 and I3 in Fig. 1 provides passage for a probe IE1; attached to a tab Ma on the firstradiator |a When energy is being carried inthe transmis sion line 5a, electric currents will be excited in J the probe l5a. Simultaneously, currents will be excited in the support Ila which currents will have a direction opposite to those excited in the probe Illa. Thus if we assume that currents are moving upward in the probe I5a, simultaneously current of equal magnitude will be moving downward in the support Ha. This isknown as balanced feed. For this reason, the current in the radiators la and 2a will be in the same direction, or in phase, and the current strength curve in the two radiators combined Ia and 2a will be as shown by the curve 1.? If each radiator Ia and 2a is one-half a wave length long, the combined radiators la and 2a together form a one wave length antenna. a I r It will be appreciated thatthe apparatus illustrated in Fig. l is substantially identical in operation to the apparatus illustrated diagrammati cally in Fig. 2a. For example, if all the elements of theapparatus of Fig. 2a be rotated 360 about the conductor la of the line 511, the apparatus of Fig. 1 will be formed. This rotation produces the solid membersof Fig.1 in place of line members as illustrated in Fig. 2. The supports it and H may be inserted in, pairs as desired, as illustrated in theapparatus of Fig.1. The radiating current will flow on. the outer surfaces of the cylindrical tubes and 2 and these tubes will then become cylindrically shaped radiators. The direction of polarization of the radiation will be longitudinal with respect to the longitudinal axis of the apparatus of Fig. 1. Theradiation should be substantially non-directional in the plane perpendicular to the said axis. Directivity of the full wave double dipole of- Fig. 1 will be had in a directionperpendicular to the aforementioned axis and a sort of doughnut-shaped beam will be produced by the antenna.

Fig. 3 illustrates an alternative form of tube II that may be used in place of the cylindrical tubes and 2 if desired. Tabs l4 may be of any number desired, the, numberand disposition of the-said tabs I4 being preferably determined empirically to afiord the desired pattern about the antenna. The tube I1 is streamlined in shape, such a shape being desired if the antenna is to be airborne; Referring now to Figs. 4, 5, and 6, there isthere illustrated an antenna comprising a plurality of substantially cylindrical radiators 2| and 22 like the radiators I and 20f Fig. 1 arranged coaxially and linearly to produce a beam having narrowtdirectivity in a direction substantially perpendicu lar to the longitudinalaxis of the apparatus, and having substantially no ,directivity about the ap paratus in a plane perpendicular to the said axis. This is known as apancake beam. The cylindrical radiators 2| and 22 are alternately placed in a linear array. Again a coaxial type transmission line 5, comprising an outer wall 6 and inner con-l 4 ductor l, is located concentrically within the radiators 2| and 22. The radiators 22 are substantially identical to the radiator 2 of Fig. 1. The radiators 2|, however are fed at both ends by probes I5 identical to the probes |5 of Fig. 1. Tabs M are provided at both ends of each radiator 2|. Three tabs I l are providedat each end of a radiator 2 I and are symmetrically'disposed thereabout. However, the tabs at one end are displaced circumferentially 60 from the tab at .the. opposite end. This provides for more uniform dispersion, or lesser directivity, in the plane about the axis of the apparatus. The feeding of the probes l5 in the apparatus of Fig. 4 is accomplished in an identical manner to the feeding of the probes 15 in the apparatus of Fig. l.

The cross sectional views of Figs. 5 and 6 illustrate'the relationship between an array of probes at one-end and an array of probes at the other end of a radiator 2|. A spider 8 (not shown in Fig. 4) is provided between each two adjacent radiators 2| and 22, respectively, for the purpose of supporting these radiators in identical fashion as the radiators and 2 of Fig-1 are supported. Holes l2 and I3 are provided where appropriate the spider 8 and the outer conductor 6 in order to permit the passage of the probes l5 into the transmission line 5.

The current distribution I on the outer surface of the radiators 2|, and 22 is shown in Fig; 4 as it may appear instantaneously. It will be noted, that eachhalf wave of the current is phasewith a neighboring half wave. This results from the fact that each of the radiators 2| having probes, is, driven at both ends. Since these radiators are substantially one-half wave length long, the probes at opposite ends are .driven'in phase opposition. Thus when the current in probes at one end is moving outward from'the transmission line to the radiator 2|, the current in the probes at the other end will be moving in-' ward from the radiator 2| to the transmission line. This will cause the current at one end of a radiator 2| to move in the same direction as the current at the other end of the said radiator at any one instant. Since, as shown in Fig. 2a the direction of the current at the end of a radiator not having a probe is the same as the direction of the current at the adjacent end of a radiator having a probe, it follows that the current on the surfaces of all theradiators 2| and 22 in the array will at any one instant have the same direction, and hence all the radiators will be driven in the same phase. For this reason, the beam produced by the antenna of Fig. 4 will have -directivity in directions perpendicular 'to'the axis of the array. Since, however, the radiators are substantially cylindrical and since thefeeding probes are symmetrically disposed thereabout and alternately staggered, the beam will be substantially non-directional in the plane perpendicular to the axis of the array. Such a beam is known as a pancake beam. e

The apparatus illustrated in Fig. '7 is another embodiment of my inv'ention for producing; a beam similar to that produced by the apparatus of Fig. 4. Substantially cylindrical half-wave radiators 3| and 32 respectively are collinearly and coaxially .aligned in a manner similar to the radiators 2| and 220i Fig. 4. Alternate radiators 3| have probes l5 at both, ends thereof supportedin tabs I4. As in the case of the radiators 2| of the apparatus of Fig.4, the radiators 3| of:-

the apparatus of Fig. '7 are driven by probesv I5.

located at both ends thereof. Thus the'currents st i 1f" dm ri' r e. e id ha f waves l fin Ph witfi h .fl h' rno eve1 $the -radiatqr sra e" support at th qen etsi ste d o tthei e th iii the 'current'I each have "theifhrgh current point near the support 33 rather than near the lim s w n t app r'a l s b i f"' Thu J I 7 probes' I5"fee'd" thetradiator "3 I at high ioltase sai 'b of t naara isi is, however,substantially identical "to' tlie"beajm of the apparatusof Eigi l', namely a panca f'b'eam lying ina" plane substantially perpendi lar to thiaxisflofth, apparamsf, v.

lthough I'have'sliown radiating elements of my nvention in" antennas for "producing" beams having af pancake "shape, it will be appreciated 1: any" one skilledfin' t e art that radiating ie'l'ein constructed "in accordance with indeparting from the invention What is claimed is:

respective passages into said 'line' through said collansaid radiators being supported at said ad'- jacejnt edges one upon said firstand the" dther l b fi's d econd fingers," Said tabs being each aligned axiallyv with a pair, of firstand secondjfingers, and three probes mounted one in and thethrebi eath"disposedpassage im'dsai i erminatingin the pace between sai'd inrier 5 d0uterconductorsT 5 Ara'dio'antenna comprising first and second spacedjradiators' having adjacent ends, a coaxial transmission line having "inner and out d conductive support" means for onma'y be"arran edinany mown" type a lf'"A'"radioante'nna comprising a plurality of collinearly disposed tubular substantially half wave length long radiators, a transmission line, and at least one probe-at e'ach end'oiea'ch alternate radiator, said probes at opposite endsof each alternate'radiat'or' beingboupled to said transmission line in such fashion as to be fed in phasebpposition by the fieldfthereof.

'Zfi'AiadiO antennacomprising"a linear rray oi'lfsubstantiallycylindrical "coaxi'ally dis ose'd sdbstantially "half wave length long radiators, a transmission line "for feeding said radiators substantially coaxially' disposedtherein, and three probes substantially symmetrically disposed about opposite ends respectively of each alternate radiator, said probes being inwardly directed into said transmission line and coupled thereto in such fashion that said probes at opposite ends of each alternate radiator are respectively fed in phase opposition by the field thereof.

3. The apparatus of claim 2 in which said probes are attached to said opposite ends at substantially symmetrically disposed circumferential points, each of the points at one end being circumterentially displaced substantially 60 degrees from the corresponding points at the other end.

4. A radio antenna comprising first and second adjacent linearly coaxially disposed substantially cylindrical substantially half wave length long radiators having adjacent edges, three axially projecting tabs on said first radiator symmetrically disposed about its adjacent edge, a coaxial transmission line having inner and outer conductors disposed substantially concentrically 1715' radio antenna comprising two elongated,- spaced, collinear; tubular radiatorsfa transits sion line extending through said 'tubulanradia tors, conductive means securing said radiators at their adjacent ends to said transmission line, and at least one probe secured to one 01. said radiators at the end thereof adjacent said other radiator, said probe being coupled to said transmission 1ine.

8. A radio antenna comprising two elongated, spaced, collinear, tubular radiators, a coaxial transmission line extending through and spaced from said radiators, conductive means securing said radiators at their adjacent ends to the outer conductor of said transmission line, and at least one probe secured to one of said radiators at the end thereof adjacent said other radiator, said probe extending into space between the conductors of said coaxial transmission line.

9. Apparatus, as defined in claim 8, wherein each of said radiators is a half wave length long.

10. A radio antenna comprising an array of axially spaced, axially aligned radiators, a transmission line for conducting energy in the direction defined by said radiators, conductive means securing said radiators at their adjacent ends to a I 7 7 said transmissionline, and atleast one conductive probe securedto each alternat radiator at each'end thereof adjacent an end of another radiator, each of'said probes being coupled to said transmission line. "11. A radio antenna comprising, an array of spaced, collinear, tubular radiators, a transmission line extending through and spaced from said radiators, conductive means securing said radiators at their adjacent ends to said transmission line, and at least one conductive probe secured to each alternate radiator at each end thereof adjacent an end of another radiator, each of said probes being coupledto said transmission line. 12. Apparatus, as defined in claim 1l,'wherein each of said radiators is one-half wave length long and wherein said transmission line is coaxially disposed within said radiators. 13. A radio antenna comprising an array of spaced, adjacent, collinearly disposed, substantially cylindrical, substantially half wave length long radiators, alternate radiators being formed with a plurality of axially projecting tabs symmetrically disposed about each end thereof adjacent another radiator, a coaxial transmission line having inner and outer conductors disposed substantially concentrically within said radiators, said outer conductor being formed with openings arranged one beneath each of said tabs, conductive spiders supporting said radiators at their adjacent ends on said line, each of said spiders comprising a substantially cylindrical collar fitted snugly on said outer conductor and a like plurality of pairs of outwardly projecting, fingers on said collar symmetrically disposed thereabout, said collar having openings formed therein one between each of said pairs of fingers, said openings in said outer conductor and said collars being mutually aligned 'to form passages through each of said collars into said line, said radiators being supported at adjacent ends thereof so that one end of one radiator is supported upon one of each of said pairs of fingers and the adjacent end of the adjacent radiator is supported upon the other of each of said pairs of fingers, said tabs each being radially aligned with a pair of fingers, and a like'plurality of probes mounted one in and through each of said tabs and extending through the therebeneath disposed pas sage into said line and terminating in the space between said conductors.

14. Apparatus, as defined in claim 18, wherein said plurality is equal to three,- each tab of. each group of three circumferentially disposed tabs being circumferentially displaced by ',60-from the corresponding tabs of any adjacent group of circumferentially disposed tabs. a

15. A radio antenna comprising an arrayof collinear, tubular radiators arranged end to end,

a transmission line extending through and spaced from said radiators, conductive means for each of said radiators disposed in a region thereof intermediate its ends and conductively securing said radiator to said transmission line, and at least one conductive probe secured to each alternate. radiator at each end thereof adjacent an end of another radiator, each of said probes being coupled to said transmission line.

16'. Apparatus as in claim 15 wherein each of said radiatorsis oneehalf wave length long.

17. A radio antenna comprising an array of adjacent, linearly, coaxially disposed, substantially cylindrical, substantially half wave length long radiators, alternate radiators being formed with axially projecting tabs symmetrically disposed about each end thereof adjacent another radiator, a coaxial transmission line having inner and outer conductors disposed substantially concentrically within said radiators, said outer con-, ductor being formed with a plurality of openings arranged one beneath each of said tabs, a support for each radiator located substantially at the longitudinal center thereof and short-circuiting said outer conductor and said radiator at said center, and a plurality of probes mounted one in and extending through each of said tabs and,

extending through the opening in the outer conductor therebeneath and into said line, each of said probes terminating in the space between said conductors.

HENRY J. RIBLET.

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

UNITED STATES PATENTS Number Riblet Oct. 25, 1949.

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