US2434925A - Coupling means for relatively movable wave guides - Google Patents

Description

' Jam, 27,1948.

.R. o. HAXBY' COUPLING MEANS .FOR RELATIVELY MOVABLE WAVE GU IDES Filed May 27, 1942 mm, m

, 'INVENTOR RQBERT O. HAXBY BY J ATTORNEY Patented Jan. 27, 1948 COUPLING MEAN SI-FCR -M v.ABLE WAVE GUIDES Robert 0. Haxby, *Hempstea'fl, N. Y assignor -to Sperry Gyroscope Company, Ind,

' -mcorporation of New 1 -1;

Application "MayJZ'l, 1942, j s v 44.56151 1 9' Claims. (Olin-M4) This invention relates, generallmito the propagation 'of electromagnetic waves along conductor means having relatively movable portions and the-"invention has reference more particularly to a novel construction of 'eoupling'meansfor transfe'rring electromagnetic-wave energyibetween said relatively movable iportions.

Specifically, the invention is adapted *fo'reflicieritly :conducting polarized electromagnetic wave=energyfrom one'wave guide'to anotherwave guide, the-wave guides "being relatively turn-able with "respect to each other.

An object of theprese'nt invention .is 10 provide meansfor -coupling -two relatively turnahle electromagnetic wave. oonducting'means whereby electromagnetic energy may vbe efiiciently transferred from one conducting means "to the other. Another object of *th e;present invention is to provide .COI'I'CQHtIiC, .line coupling means "between two re'latively turnable'wave guides, said coupling means bGiHQ'fSO designed as to enable the efficient passage "of polarized electromagnetic waves from one wave guide through the coupling means and 'intdthe other :guide.

' Another object of the fpresent invention 'is to provide'means fortconducting andradiatingelectromagn'eti'c energ'y'at varying angles comprising astationary wave uide-andsrelatively movable emitting wave guide "together with *means for interconnecting said wave "guides for "conveying the energy therebetween iinian 'efiicientrmanner. Still another object of the 'presentiinvention is to jprovide relatively Ltm'nahle wave 1 guides hav ing fan interconnectin concentric line section, the outer conductor ofwhich section is divided .tetenable relativeituming movement-between said waveguides,means'heingprovidedttoreducethe escape of 'energy'through' said divided outer eonductorto a minimum,

:Another object of the v present invention "is to provide "relatively turnable 'wave guide together with coupling means therefor comprising" a con centric line structure having relatively turnable outer and inner conduetors, theinner'conduotor being integral throughout ;its lfength to obtain operating gflicienc yand the "outer conductor being broken to enable relative movementof the two'wavej'guides, suitable-wave trap means being provided in connection with said outer conductor to reduce escape of;energy'there'fromto ayminimum. V I

A still further oliject of the" present invention is'to, providemeansifor e'iiiciently:coupiin a wave guide type transmissioniineito. a eoncentric type transmission line, such coupling "means dieing adapted to operate over a relatively large'ranse of operating irequencies without-creating objectionable standing waves in either the wave guide or concentrictransmission line.

Other objects and advantages will become apparent from the specificationtaken in connee= ti'on with the accompanying drawing wherein the single figure shows one embodiment of the-in- Vention. I

Referring now tothe drawing, the reference numerals 2 and 3 designate waveguides shown as "of rectangular form and adapted to convey polarized waves, :said wave guides being'interconnected by the novel coupling means of this invention. "This oouplingmeans comprises a eoncentrie line structure consisting of a unitary inner c nductor v and a divided outer conductor consisting 46f nnarts'ili. i and "I. 'i'l' router conductor sentient-is provided with anexternalpro- 'jection'28 whichis sockete'd for receiving the end portion or the guide 2, such end portion -lacing securedito the projection 28 ashyscrews .9. "The portionyof "the projection 28 opposite "the end of guidezis provided'with atunin plug 31 adjuStablebys'et screw's'5'l. Element 20 is a rectangulai' piugifittirlg within the portion of pro ection il'2,. itu'ated at the closed end of waveguide and looked in liilace by a lockin crlew t3. its function is to provide an adjustable means .iior matehing'gthe impedaneeoi'guide 3 to that to the concentric fline v.eonditcitor. "The rprqiectmneza is provided witn'an annular extension'sz surround: ingtthe outereonoentric line 'conducitdr' sect on"! and spaced.somewhattnerefrem,{said extension having a ollars I secured, thereto-fishyscrewsjsa, which collar is internally recessed ,jfoir receiving an.anti:frietionhearingt0supportin tlie portion 1 of the {outer conductor; of the concentric line.

@A tuning .p1ug:26 Jis adiustablv slidable within outer conductor portion'1 and over the, inner conduetor 4 by means of a .knob' 38 and eonne tin roasts. fiTheciollarfli ovidedwith aninner annular proiectionis r' gnaving a reduced endpo'rtion 3| paced radiallyiboth irom the extension 32 and iron tne outer conductor portion 1 whereby an i annularreeesjs:34 elosediattheilower end'is nrovided'between extension "32; and reduced portionsr" t provrde-a wavetrap-andimpedanee matching device, as will "further appear.

As" thusly constructed, the outer conduc'torflpor tion '1 together with "the inner conductor f4 and plug 26 ,are fitee'" to turn ass; ,unitwithin collar 3| and extensional; the inner end oi-ou er onduc torfportionflmaving'asligliteiearane withers;

-snect -to"theopposingendofportionli erthe outer 3 conductor as shown at 29. Thus, the bearing 30 serves to rotatably support the outer conductor portion 1 within the extension 32, this extension, it will be noted, being attached to the wave uide 2.

The outer conductor portion 6 of the concentric line coupling is provided with a tuning plug 2I slidable therein,the,, adjustment of this tuning plug being provided for by means of a nut 22 engaging threads 23 on the outer surface of outer conductor portion 6. Nut 22 is provided with an internal annular slot for receiving transverse pins 24 fixed upon the plug 2I, which in turn slide in longitudinal slots 53 in conductor portion 6. Hence, by turning nut 22 the plug 2|.is adjustable longitudinally within outer conductor portion 6 and along inner conductor 4. Thus, it will be noted that the inner conductor'4 of the guide-2 through theconcentric line shown and concentric line is supported at one end. within 1 plug 2| and at its other end portion within the plug 26.

Wave guide 3 is fastened to portion 6 in the same manner as guide 2 is to portion 5. Outer conductor portion 6 is also provided with an annular extension I5 surrounding and spaced from the portion 5 of the outer conductor. A collar 40 is secured to the extension I5 as by screws 33 and is internally recessed for receiving an anti-friction bearing I9 interpositioned between this collar and the outer conductor portion 5, which is secured to wave guide 2. The outer conductor portion 5 terminates adjacent to, and has a slight clearance as indicated at I4 from the outer conductor portion'6. The collar 40 is provided with an inner annular projection 40' having a reduced end portion 40" spaced radially'both from the extension I5 and from the outer conductor portion 5. Here again an annular recess I6 closed at one end is formed between extension I5 and reduced portion 40" to provide a wave trap and impedance matching device, as will further appear.

The inner conductor 4 is shown provided with somewhat enlarged portions l and I I smoothly connected to the main conductor 4 at the points where guides 2 and 3 connect with the concentric line, which enlargements, in cooperation with substantially conformably shaped curvilinearly flared bore portions 6 and formed in outer conductors 6 and 5, respectively, enhance the chiciency of the energy transferred, and also are believed. to increase the allowable frequency range of the transferred energy.

As thus constructed, it will be noted that guides 2 and 3 are relatively turnable. In this connection it will be noted that guide 3 together with inner conductor 4, outer conductor portion 6, and outer conductor portion I and connected parts, are turnable by means'of bearings I3 and 30 with respect to the outer conductor portion 5, extension 32 and wave guide 2.

In. operation, assuming vertically polarized electromagnetic wave energy is supplied to guide 2 moving from left to right in the figure along guide 2, then the energy is picked ofi by the en-- larg'ed portion I0 of the inner conductor 4 of the concentric line, so that the electric vectors defining the direction of the electric field take up radial positions within this line, resulting in upward movement of energy which is conveyed to the upper end thereof and is reradiated into the guide 3 in the converse manner as vertically polarized energy. This guide is shown twisted at M so that this vertically polarized energy becomes horizontally polarized at the portion 42, of the guide.

'into guide 3, or vice versa, and the construction shown substantially eliminates any escape of energyfromthe divided outer conductor 5, 6, I.

In this connection it will be noted that a chamber I6 is providedexteriorly of outer conductor portion 5 communicating with the radial clearance opening I4 between outer conductor portions 5 and 6. The length of the annular chamber I6 corresponds to substantially a quarter wavelength of'the energy being transmitted and hence elfectively forms a wave trap. For efficient operation the impedance at the gap I4 should be low in order to enable currents to flow readily between outer conductor portions 5 and 6. The end of the wave trap space I6 removed from the gap I4 should therefore have a high impedance and this is insured by an additional wave trap l6 provided between the extensions I5 and 40", this wave trap also being substantially a quarter wavelength in length and short-circuited at its remote end. Thus, with a current node-provided at the end of the wave trap I6 adjoining wave trap I6 a current maximum is provided at the gap I4 representing a low impedance at this point. Since a current node occurs at the junctures of these two wave traps substantially no energy escapes down the annular slot between outer conductor portion 5 and sleeve 40 through the anti-- friction bearing shown. This is highly desirable since it not only prevents the escape of energy but also prevents overheating of the bearing. Furthermore, the undeterminable impedance between conductor 5 and collar extension 40, caused by leakage of energy and conditions external to the apparatus, is rendered inefl'ective to change any conditions at the gap I4 by being efiectively connected in series with the very high impedance of quarter-wave-shorted section I6. A similar wave trap and impedance matching construction is provided by spaces 34 and 34' associated with outer conductor portions 6 and 1 of the concentric line so that a low impedance obtains at gap 29, enabling the ready flow oftcurrent along the outer conductor but preventing the escape of energyto or through the bearing 36. As many changes could be made and many widely different embodiments of this invention could be made without departing from the scope thereof it is intended that all matter given 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:v 1. In a structure of the character described, a pair of relatively turnable wave guides and a concentric transmission line coupling said wave guides, said transmission line comprising an outer conductor portion fixed to one wave guide, bearings provided upon said outer conductor pore tion, additional outer conductor portions carried by said bearings and relatively turnable withrespect to said first-mentioned outer conductor portion and connected to said other wave guide,

maid iconcentric nine coupiin'g tits anner conductor ssupp ort'ed ss'aid saddit'ionai mater nonductoripoiitions.

a2. :a structure-Mime characteridescribenm pair of neiativeiy iturnaple 'awave gtu'des :and 2a a concentric iiirre :con'ductor coupling :said wave guides, 'Isai'd conductor icomprising an fouter Icon-'- ductor :portion :fixedato tone wave de, :bearings provided uponssaid router "conductor aiportioh, ad-

:ditional outer :conductormoittiohs zcarriedtbyzfsaid bearings zand a'rela-tively rturnable with zrespect to said;- firs't-mentioned outerizconditctoriporttonsand connected to :Lsaid oth-er mane iguide, ai'd econcentri'c nine icouplingxhaving its inner conductor suppontedi trom 1 additional outer :conductor iipor t internal conductors, the ends of saidguides tera minating in surrounding :re-la'ti'on to =the inner conducmr of said concentric :line coupling, :said innerconductor being of:expanded diameter withinisaidr-guides and means =for tnning the guides to ithe rconcentric line coupling and fortuning i .th zends of ..said line coupling.

4. An ultra high frequency apparatus 5.80m-

,pnising a con'centric line having :a unitaryzinner conductor and an outer conductor, sai'd foutcr conductor vhaving two tspa'ced ss'ections' ":fi'xedly connected to said inner conductor, andz a'lso havingfai further section between said two ispa'ced sections and rotatable with respect thereto, and wave trap means at the gaps between said rotatable section and said spaced sections for preventing leakage of energy through said gaps.

5. In an electromagnetic wave conducting means having relatively turnable sections and an interconnecting section having relatively turnable portions, means for securing the relatively turnable portions of said interconnecting section to said respective turnable sections, and wave trap means for preventing the escape of energy through the gap between the relatively turnable portions of said interconnecting section.

6. Apparatus as in claim 5, wherein said wave trap means comprises a quarter wave concentric transmission line section concentric with said interconnecting section connected at one end to said gap and at the other end to a further shortcircuited quarter-wave line concentric to said interconnecting section, said short-circuited line being connected in series with the escape path of said energy.

'I. An ultra high frequency coupling between a pair of axially aligned tubular conductors having a narrow gap therebetween, comprising an expanded portion formed on one of said conductors and surrounding the other conductor in spaced relation thereto whereby said expanded portion and said other conductor form a concentric transmission line section, a sleeve member connected to said expanded portion at the end remote from said gap and extending axially between said expanded portion and said other conductor to a point spaced from said gap such that the length of said concentric transmission lin section is substantially equal to a quarter wavelength at the operating frequency, said sleeve member having a. portion of reduced thickness atitheifreeiend;triereonspacedzfrcncsaidiwpanded 'nottiommaidrerlucedithiclmess;portienioeingssum stanti'a'ilyzzamuaritertwavelengthflongiattthezcper concentric line havingzta dividedput'er iconduct'or aipcrtion so which is 'ifixe'dly connected Ijto :s'aid way "iguidesand an'othertportionrof lwhi chzzisrrelaturnable with respect theneto :and @wave 'itraplmeans-ixzonnectedibetween ."said1portions;.said

Wave atra-p .:means :comprising 7a i pair -:of serially fc'onnected quarter vwaveleng-th .transmission :line sections 'providi-ngr azrel'ativelyfalow impedance rat the Junction :of ssaid iou'ter rconductor mortioirs.

1J9. aUltra xfrequency'zenergy conducting anparatus comprisingasaisection of concentrictransmission line-having an I inner conductor and an 'outer :condu'ctor, said outer;conductor;being::sep-

and coupling z'means for abstracting high :f-renuency ener-gy-i from one of said router ssections :of tout-er conductor whereby visa-id .two coupling means r-m-aysbe relatively rotated =with respcct to one another.

11. Apparatus as in claim 9, further including means for coupling high frequency energy to the center section of said outer conductor whereby Said coupling means is relatively rotatable with respect to said inner conductor and said other outer conductor sections.

12. Apparatus as in claim 9, further comprising an ultra high frequency wave guide and means for coupling said wave guide to said center section of outer conductor and to said inner conductor whereby, said wave guide may be rotated relatively to said transmission line section while transferring energy therebetween.

13. A concentric transmission line for interconnecting two relatively turnable wave guides, comprising a unitary inner conductor and an outer conductor divided into a plurality of portions, said portions forming with said inner conductor concentric transmission line sections of substantially equal characteristic impedance, one of said portions being secured to one wave guide and another of said portions being secured to a second wave guide, and means for preventing the escape of energy from between said outer conductor portions comprising a pair of serially connected quarter wavelength transmission line sections providing a relatively low impedance at the gap between said outer conductor portions.

14. In combination, a wave guide, a coaxial transmission line having spaced outer and inner conductors, said wave guide and said line having mutually orthogonal axes of energy propagation, a curvilinearly flared connection between the outer'conductor of said coaxial transmission line and said wave guide, and an expanded-diameter termination on said inner conductor projecting transversely within said wave guide.

15. An ultra high frequency energylcoupling junction comprising a wave guide of rectangular cross-section having aligned apertures formed in opposed side walls thereof and a pair of con centric transmission line sections having a common unitary inner conductor and axially aligned spaced outer conductors, said inner conductor ex tending through said apertures of said wave guide, the portion of said inner conductor contained within said guide being of expanded diameter, and flared connecting means connecting said outer conductors to said side walls of said wave guide at the apertures therein.

' 16. Ultra high frequency apparatus comprising a pair of wave guides and coupling ,means interconnecting said. wave guides, said coupling means comprising a concentric: transmission line section having inner and outer conductors, said inner conductor extending through each of said wave guides with the portions thereof within said guides being of expanded diameter, and flared connecting means joining saidouter conductor to a wall of each of said wave guides.

17. Apparatus as in claim 16% wherein said expanded-diameter portions are of substantially ellipsoidal contour cooperable with said flared connecting means, whereby substantially increased bandwidth of operation is obtained.

18. Conductor means for conveying electromagnetic waves comprising two relatively tumable wave guides and an interconnecting concentric line, said concentric line having its outer conductor divided into a plurality of portions, one of which portions is secured to one wave guide and another of which portions is secured to the other wave guide, bearing means provided between said outer conductor portions, and means for preventing the escape of energy outwardly from between said outer conductor portions, said last-named means comprising a wave trap having a low impedance looking at the juncture of said outer conductor portions and a high impedance looking away from said juncture.

19. Conductor means for conveying electromagnetic waves comprising two relatively turnable wave guides and an interconnecting concentric line, said concentric lin having its outer conductor divided into a plurality of portions, one of which portions is secured to one wave guide and another of which portions is secured to the other wave guide, and means for preventing the escape of energy outwardly from between said outer conductor portions, said preventing means comprising a wave trap having a low impedance looking at the juncture of said outer conductor portions and a high impedance looking away from said juncture.

ROBERT O. HAXBY.

REFERENCES crrnn 'I he following references are of record in the file of this patent:

UNITED STATES PATENTS Number 2,239,724 Lindenblad Ap1229, 1941

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