US2954559A - Prefabricated sleeve antenna - Google Patents

Description

Sept. 27, 1960 A. A. YUREK ETAL 2,954,559

PREFABRICATED SLEEVE ANTENNA Filed March 24, 1959 5 Sheets-Sheet 1 FIG. I PRIOR ART INVENTORS k 4% ,,--ALLEN A. YUREK l8 PAUL L. WEBB BY CQ zmm ATTORNEYS P 1960 A. A. YUREK ETAL 2,954,559

PREFABRIC'ATED SLEEVE ANTENNA Filed March 24, 1959 5 Sheets-Sheet 2 as in? 60 FIG. 2 Ill! Lil 33 21 I l 3| Iii 37a 5 37b INVENTORS ALLEN-A.YL JREK PAUL L. WEBB MK 47 63 BY l6 M %1/8 P 27, 1960 A. A. YUREK ET AL 2,954,559

PREFABRICATED SLEEVE ANTENNA F'iled March 24, 1959 5 Sheets-Sheet 5 FIG.3

FIG.4

ALLEN A. YUREK PAUL L. WEBB ATTORNEYS 62 INVENTORS Sept. 27, 1960 Filed March 24. 1959 0 ,1] 410g \qoo,ooooooooooo A. A. YUREK ET AL PREFABRICATED SLEEVE ANTENNA 5 Sheets-Sheet 4 FIG.?

IN VENTORS ALLEN A.YUREK PAUL L. ,WEBB

ATTORNEYS Sept. 27, 1960 A. A. YUREK ETAL PREFABRICATED SLEEVE ANTENNA 5 Sheets-Sheet 5 Filed March 24, 1959 FIG. 8

w H I W mu 9 w k -E M F ml.

S S R Y m m W m W w L mm AP Patented Sept." 27, 1960 PREFABRICA'I'ED SLEEVE ANTENNA Allen A. Yurek, Camp Springs, Md. (6012 Merchant Road, Washington 22, D.C.), and Paul L. Webb, 313 Branch Circle, Vienna, Va.

Filed Mar. 24, 1959, Ser. No. 801,676

3 Claims. (Cl. 343-875) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States have involved the fabrication of the antenna around a telegraph pole or similar type pole assembly of a character which was permanently set in the ground at the antenna site. From this pole and minor prefabricated parts of a character which will become more apparent as the description proceeds the construction was made. This type of an installation presented certain disadvantages in that each antenna had to be tailor made at the predetermined site and assembled about the previously erected pole. A particular shortcoming resided in the fact that if by chance this location was subsequently determined or proven to be unsatisfactory after erection and test of the antenna the antenna could not be moved, consequently a new antenna would have to be fabricated for trial and error testing at the new 'location. Repeated efforts of this nature might be required before the most desirable site for the installation had been obtained.

Certain disadvantages are inherent in the prior type of antenna installations, while othershortcomings of a nature preventing the obtaining optimum electrical performance characteristics arise from the fact that such types of antennas could not be held within required tolerances to insure reproducibility of certain of the electrical characteristics with successive installations.

This situation is contributed to by many factors including'the displacement of the antenna base insulator with respect to the base of the antenna, which is in part due to the necessity for attaching counterweight structure at the base of the antenna for maintaining structural rigidity of the antenna sleeve and to maintain the antenna cage taut. Also the use of strain insulators contributed in part to the undesired situation. Other factors include the utilization of steel guy lines from the telegraph pole which were necessary for support thereof together with the resultant impedance mismatch conditions which occur with the particular type of coupling of the antenna transformer section at the point of termination, etc.

The novel structure and method of prefabricating the antenna of the instant invention, together with the improvements in structure and electrical characteristics, of which all factors are of a nature contributing to an overall improvement, both in antenna performance and mobility, erectability and ability to disassemble andrelocate the States Patent antenna in a minimum period of time will become more apparent as the description proceeds.

It is a feature of the instant invention to provide a high performance, high reliability sleeve-type antenna structure of a prefabricated nature which can be assembled on a proposed site with a minimum amount of equipment and which provides a maximum degree of reproducibility of electrical characteristics of the system.

Another important feature of the invention resides in the fact that this particular type of antenna system requires no auxiliary supporting structures other than the guy lines, thus every element of supporting structure has an electrical purpose or is a functional part of the antenna system.

One object of the instant invention resides in the provision of an improved sleeve-type antenna which can be prefabricated in sectional form from rigid elements of a character providing for nesting of similar" structural units for packaging and transporting while providing a high degree of rigidity when assembled and yet presenting a I high degree of simplicity in the assembly operation required for erection of the antenna system.

Another object resides in the provision of a basic type of prefabricated sleeve-type antenna system which is well adapted for utilization in any of a plurality of sizes for high performance broad bandwidth usage for a plurality of differing frequency ranges.

Another object of the invention resides in the provision of a sleeve-type antenna structure which minimizes to a very substantial degree the many variable factors normally encountered in antenna erection of prior type antennas and which variables are generally of a nature contributing to differences in performance characteristics thereof.

Another object of the invention resides in the provision of a prefabricated sleeve-type antenna structure which is of such design that when erected a substantial number of the shortcomings of prior antenna structures heretofore or now in general use are obviated while providing substantially all of the desired features thereof without sacrifice in structural rigidity.

In correlation with the foregoing object it is a further object to provide improved performance and almost ideal reproducibility of performance between like antenna systems of the same design when erected cated subassembly units.

Another object of the instant invention resides in the provision "of prefabricated sleeve-type antenna structure which is well adapted for utilization on arctic and polar expeditions wherein the antenna system may be conviently erected and subsequently disassembled after serving a desired use at one location and can thereafter be readily transported to other locations without the necessity for transport and erection of telegraph-type poles at each selected antenna site.

Another object of the instant invention resides in the provision of an antenna system which can be prefabricated, packaged and transported to an erection site and the structure erected at a substantial saving in overall cost compared to antenna structures for similar purposes and of the character heretofore or now in general use.

Another object of the instant invention is the provision of a prefabricated structure of such design that each section will nest into its mating section for packaging in a package of substantially cubic dimensions, which package includes all necessary ground radials, ground rods, transformer trunk sections, skirt sections and antenna sections and wherein it is visualized that such antenna or components thereof may be prefabriwith like prefabricated at any of a plurality of manufacturing plants with In correlation with; the immediately foregoing object, it is a further object that whenantenna structures of the instant character are stored in a manner as above set forth, and when one is called upon to furnish such an antennaofthis-type, it couldj be drawn from stock as any other semiportable: or prepackaged unit is now drawn; thus-eliminatingtheneed for long lead times which: are frequentlynecessary for procurement and as: semblyof: parts of the character utilizediin prior or presently utilized antenna systems ofacharacter other than that of theinstant invention.

Another objectofthe instantinvention resides in the utilization of continuous insulators of organic plastic cord materials as guying elements for the antenna sleeve in lieu of conventional guy Wires having a plurality of alternately and intermittently spaced discrete insulators disposed between segments of the guy cable elements as utilized in prior art devices.

Other objects and many of the attendant advantages of this invention will be readily understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: Fig. 1 is an elevation view with portions broken away of a sleeve-type antenna system of the prior art character;

Fig. 2 is a pictorial illustration of a prefabricated sleeve-type antenna of improved structural and electrical characteristics as embodied in the instant invention;

Fig. 3 is an enlarged fragmentary elevation view of the interconnecting sections of an antenna sleeve of the instant invention as shown in Fig 2;

Fig. 4 is a fragmentary elevation view of typical sections of the shielding tower support for the sleeve antenna of Fig. 3 showing the details of construction and manner of assembly with other of the prefabricated tower elements of the instant invention;

Fig. 5 is a view taken along the line '5-5 of Fig. 3 and shows details of the lower central flange of the antenna sleeve;

' Fig. '6 is a fragmentary plan view of the lower corner portions of the base of the shielding tower of Fig. 4 and taken along lines 6-6;

Fig. 7 is a detail plan view of the uppermost section of the shielding tower taken along lines 7-7'of Fig. 4;

Fig. 8 is a fragmentary view in elevation illustrating the details 'of' the impedance matching transformer or coaxial line feeder trunk for a transmitting antenna with portions thereof'shown in section; and v Fig. 9 is a view similar to the upper portion of Fig. 8 showing details of the coaxial line connection to the base of the antenna sleeve for a receiving type installation.

Referring now to Fig. 1 for a showing of a prior art type of sleeve antenna structure in order to provide a clearer understanding of the instant invention and to more particularly point out or make more'evident the respective structu'ral diiferences over which prior structure the instant invention provides certain of the aforementioned structural and electrical advantages. The priorart sleeve antenna generally indicated at 1is supported from a mast arm 2 carried by the vertical'mast 3'WhlCl'l is generally in the .nature of a telegraph pole or the like. The antenna sleeve 1 is supported from a suitable insulator 4"disposed at the upper end thereof and connected by means of eye-elements 5 to a short supporting .wire 6 which extends from the-top of the mast or pole 3 to the outer end of the cantilever mounted antenna support arm 2; Centrally disposed along the mast is an intermediate insulated standoff support 17. The lower end of'the antenna sleevel is connected by means of insulator 8} to a cable 9 which is in turn connected to a counterweight mass 11 disposed within the shielding tower; structure 12. The electrical termination of the sleeve antenna .1 is by means of a jumper 13 connected between the lower end of the antenna sleeve 1 and the standoff insulator 14. The shielding base .12

comprises a rugged framed structure of timber elements which are braced, in a manner not shown, to the telegraph pole 3 and a shorter pole 15 which extends substantially from the ground to a height above the top platform 16 of the shielding tower 12. The vertical shielding members 17 are metallic rods disposed about the periphery of the shield structure and running from the top 16 downto the ground levelthereof. The ground radial members 18 are laid out in a radial manner from the geometric'center'of the;base of the shield structure 12'and have the outer ends thereof connected by a peripheral conductor in a manner substantially as shown for the structure.of 'Fig.;.2.. The antenna transformer or feeder trunk shown at 19 is provided with a bend at 21 for transitionfrom a horizontal run to a vertical run which extends upwardto terminate at the insulating connector 22 substantially as shown.

The mast is guyed in a vertical position by means of a plurality of (generally three) guy wire assemblies 23 which are made up of alternate sections of wire cable 24 isolated at discrete points along the length thereof by suitable guyinginsulating members 25 of a conventional nature.

Referring now to Figs. 2 through 9, there is a showing of the improved antenna structure of .the instant invention. The systemis erected on a suitable footing as indicated generally on Fig. 6. The antenna sleeve indicated generally at 31, Figs. 2 and 3, comprises a plurality of rod-like elements 26 which are suitably afiixed as by welding to a plurality of ring members 27, and which terminate intip members 28 and 29 respectively at'the upper and'lower ends of the sleeve 31. The sleeve assembly 31 is comprised of a plurality of four or more segmental sections 32, 33, 34 and 35 which are connected together by annular flange elements 36a, 36b, 37a, 37b, 38a and 38b. Thiststructure is shown in greater detail in the exploded view of Fig. 3. This structural assembly is supported from an insulated supporting block assembly 39 fixedly mounted with respect to the platform 41 of the shielding tower structure 42in a manner to be hereinafter described.

The sleeve element 31 is suitably guyed by a plurality of guying assemblies 43 which are of a Dacron plastic cord material 'and'serve the function of normal guy wires, but which are of the nature of continuous electrical insulators. The guy cords 44 of these assemblies 43 are suitably attached to the central portion of the antenna sleeve by eye-members 45, Fig. 5, provided on the flanged element 37b. The guy cords are staked to the ground at the remote ends by suitable stake elements 46. Both ends of" the guy cords are terminated by eye-splice type cable clamps at 47 of a character well known in the art.

The tower 42, which is both a support to increase the effective radiation pattern of the antenna and a shielding tower, comprises a plurality of (in the embodiment shown three sections) frusto- pyramidal sections 48, 49 and 51 of rectangular plan configuration. The sections as shown in greater detail in Fig. 4 are made up of Welded angle sections to provide the four corner elements and the upper and lower rectangular base flange weldments. The tower sections 48, 49 and 51 are so dimensioned that the lower base 52a of the intermediate section 49 is of mating size with the upper frame flange 52b of the lower section 51, and the uppermost frusto-pyramidal section has a base flange 53a which mates with the upper frame.

platform 41 is provided with a suitable aperture at 56v for fixedly mountingthe insulating base block assemblyv This base assembly is pro- 39 for the antenna sleeve. vided with, a cylindrical socket portion 57 for mating reception of the lower end of the antenna sleeve and is retained therein by' a suitable pin locked nut 58 and' threaded plug connection at 59 of Figs. 8 or 9 as the case may be to provide for electrical connection to the transmitting transformer trunk or the receiving antenna coaxial cable connection as hereinafter described in greater detail. The three sections which form the shielding support for the sleeve antenna are provided with a plurality of longitudinally extending rod elements which are disposed in substantially equal spaced relationship and Welded in place about the periphery thereof substantially as shown. The ground plane radials 62 for this antenna are of a character similar to that of Fig. l in that the radials extend from the shield base along a line projecting from a point at the geometric center of the shielding base outwardly therefrom to a suitable length such for example as 40 feet, and in 2 degree angular spacing intervals. They have the outer or terminal ends thereof connected by a perpheral conductor 63 as by soldering. The inner ends of the ground radials are brought up through suitable holes in the base flange member 65.

It will be apparent that in the disassembled form, the

plurality of prefabricated framed sections of the shielding base structure for the sleeve antenna may be nested to provide a compact relationship for handling in a convenient package arrangement of minimum dimensions commensurate with maximum flexibility of assembly at the installation site. In assembling the antenna the three sections 48, 49 and 51 of the shielding tower structure are assembled in building block fashion and bolted together as shown at 67 by means of a plurality of drilled holes 66 provided on the peripheral edges of the mating flange elements of respective adjacent sections. It will thus be apparent that an extremely rigid shielding'tower type support is provided which can be assembled with a minimum of tools and without the necessity for utilization of telegraph poles or the like type elements in the tower structure.

Referring now to Fig. 3 .the antenna sleeve proper is shown on an enlarged scale to illustrate the manner in which the copper clad iron rods 26 of the terminal conic sections and the intermediate frusto-conical sections are welded about the periphery of the flange rings 36a, 36b, 37a, 37b, 38a and 38b and are in turn connected to the holes 69 in the adjacent abutting sections. The lowermost end of the antenna cone section 35 is terminated in a threaded cylindrical plug shaped portion at 59 which is internally bored at 71. The bore 71 is adapted to receive a male connecting element 72 which extends through the lower insulating support block 73 mounted on the uppermost deck plate 74 of the shielding tower. The antenna structure hereinbefore described may be used either for transmitting or receiving purposes depending upon the type of coaxial line used therewith. The details of the coaxial transmission line structure are of a conventional nature but are hereinafter described for purposes of co i-- pleteness. The afore-mentioned rings for the guy cords are shown at 45 (with three utilized in the instant case) and are suitably welded to the flange 37a substantially as shown. The staking down of the opposite ends of the guy cords at the earth surface completes the structural portion of the sleeve and tower assembly.

Referring now to Figs. 8 and 9 the variations of the parts incorporated for assembly of the insulating support block will first be described for a transmitting type coaxial transmission line for electrical connection to the antenna sleeve. This structure is shown to include an additional flanged plug type bushing 75 of insulating material which is inserted in a bore 76 in block 73 for aligned reception with the plug portion 59 of the an tenna sleeve whereby the metallic flanged stud like connecting element 72 may be conveniently inserted and fastened in bore 77 thereof prior to insertion into bore 76. A suitable pin or plug type connector portion 78 6 is provided on the opposite side thereof for electrical connection to the antenna trunk, or transformer section. The antenna trunk 79 or impedance matching transformer comprises :a concentric arrangement of copper tubing or the like at 81 and 82 which is spaced in concentric relationship by a plurality of generally annular insulating washers 83 having flats at 84 for free passage of drying gas along the length of the trunk. They maintain the spacing between the outer diameter of the inner tube and the inner diameter of the outer tube section. A pair of counterbored blocks 85 and 86 are bolted in place to provide register seats and an airtight joint be tween the trunk 79 and the connector '75. An O-rin-g seat is provided at 87 substantially as shown.

The intermediate sections of the trunk are adapted to 'be connected by means of flange joints 88 which are bolted together at '89 in a well-known manner. The trunk is made in sections to facilitate packaging. It is maintained airtight .by the incorporation of suitable gaskets or O-rings not shown between adjacent flanges. The upper end of the trunk is retained by flange 92 which is fixed to tube 81 and retained by the extension portion of bolts 93. Preferably the trunk is provided within a suitable fitting at 91 for internal pressurization with a drying gas in a well-known manner.

The receiving antenna connection from. a conventional coaxial cable 94 is made by mating coaxial cable conductor parts 95 and 96. The flange panel portion 96 of this connection is .aflixed to plate 74 in any desired manner. A pin extension 97 is soldered on the internal solder type terminal thereof to extend into bore 71.

Obviously many modifications and variations of the present invention are possible in the light of the above .1 teachings. 'It is therefore to be understood that within tenna' and shielded supporting tower system of the type described, comprising an antenna sleeve comprised of a plurality of cage-like elements and a pair of truncated righ-t conic section-like elements, said cage-like elements comprising a pair of spaced flanges and. a plurality of rod-like elements connecting said spaced flanges, said right conic section-like members comprising a flange, a tip member spaced from the flange and a plurality of rod-like elements connecting said flange and said tip member, one of said flanges on each cage-like element having a different diameter than the other of said flanges but having the same diameter as the next adjacent flange of the next adjacent element such that when the elements are connected a double-ended right cone configuration is achieved, means for securing said cagelike elements and said right conic section-like elements together to form an assembled antenna sleeve, a shielded supporting tower comprising a plurality of prefabricated pyramidal elements having an upper and a lower (frame member, vertically extending members connecting the upper and lower frame members and a plurality of shielding rods attached to the frame members in equally spaced relation about the outer peripheral edge, the lower frame member of each pyramidal element having a greater inside length and width than the outside length and width of the upper frame member of that element and the lower frame member of each pyramidal element having the same outside length and width as the upper frame member of the next adjacent pyramidal element such that the uppermost pyramidal element will nest within the next adjacent pyramidal element and this pyramidal element will nest within the next adjacent lower pyramidal element, such that the entire tower may be transported or handled as a package the size of the lowermost pyramidal element, a uniform potential grounding system comprising a plurality of radially disposed conducting elements extending outwardly from the-uppermost pyramidal element of said tower for are:

movable mounting reception of the lowerend of said antenna sleeve, said supporting means being of a material-providing electrical insulation of said'sleeve with respectto said shielding tower, an impedance matching coaxial transmission line connected to extend at least from the tower base through the interior of saidtower to-said-antenna sleeve, and a plurality of guying means attached to extend between the-centermost flange of said antenna sleeve and-the earth ground.

2; A high performance prefabricated sleeve-type antenna and shielded supporting tower system for providi-ng-improved performance and-signal to'noise ratio characteristics comprising in combination a shielding tower comprising a plurality of pyramidal elements having anupper and-a lower-frame member, members connecting said upper and lower frame members and shielding means disposedabout theperipheral surfaces of said frame members, the lower frame member of each pyramidalelement having a greater inside length and width than' the-outside lengthand width of the upper frame-member' ofthat element and the lower frame member of each pyramidal element having the same outside length' and width as the upper frame member of the "next adjacent pyramidal element such thatthe pyramidal elements will nest within the nextadjacent lower element to provide a package the size of the base pyramidal element-for handling and transporting, insulating supporting means mounted on the uppermost pyramidal element of'saiditower for removable receptionof the lower;- end of a sleeve-type antenna, a prefabricated sleeve-type antenna comprising a plurality of sections, each ofisaidsections having spaced flanges of different diameters connected by rod-like elements, means forsecuring said sectionstogether to form an assembled sleeve-type. antenna, the flanges of each section having thesarneidiameter as the flange'of the next adjacent section such that when secured together a double-ended cone configuration is achieved, means mounting said antenna sleeve; at its lower apex onsaid supporting means; guying ms-ans attached to extend between the antenna-andthe ground, a uniform potential grounding systemcomprising a plurality of peripherally interconnected electrically. conducting radial elements extending outwardly'fromthebase of said tower and connected thereto, and-acoaxia1 transmission'line connected to said antenna and extending through the inside-ofsaid towerto the base thereof, said means for mounting the antenna sleeve comprising an electrical conduction-elernent'within said insulating supportingmeans forelectr'ical connect-i'on'with said coaxial line.

3; Thestructural combination of claim 2 furtherincluding in combination an impedance matching antenna coupling transformer of a character comprisinga pressurizedcoaxialtrunk extendingfor electrical-connection with said antennasleeve-to the base frame of said tower and having atransitionmember projecting laterally substautially in the ground-"plane from below the terminal portion-of"thetower to a point external theretorand further characterizedin-thatthe guying means is. composedfofamaterialjpossessing high dielectric constant characteristics and-providing high tensilestrength'characteristics thereby to' provide. a continuous insulator type guyingsysteln for said antenna.

References Cited in the file of this patent UNITED STATES. PATENTS,

OTHER REFERENCES Construction of anExperimentalFMtAntenna by Sleeper, FM and, Television, April 1946, pages 23 to-29.

Images