US1928645A

US1928645A - Antenna system

Info

Publication number: US1928645A
Application number: US476688A
Authority: US
Inventors: Jennings B Dow
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-08-20
Filing date: 1930-08-20
Publication date: 1933-10-03
Anticipated expiration: 1950-10-03

Description

Oct. 3, 1933. J. B. DOW

ANTENNA SYSTEM Filed Aug. 20, 1950 )NVENTORJ AT ORNEY Q imlwli Patented Oct. 3, 1933 Q remnan s the at of time 3; 1833, as amended April 30, 1928; 3'70 0. 757) 1 My invention relates broadly to directional radio communication systems I and j more I particularly to the constructionof an antenna for use in such systems.

-55 One or the objects of my invention is to provide a construction of beam antenna system for operation in directional signaling systems having a a minimum number ofparts and adapted to be readily erected and adjusted. j m

Another object of my inventionis to provide v. a simplified construction or beam antenna for directive signaling systems adapted to be readily adjusted for both long and short wave trans-1 mission and having means for adjusting the direction in which the antenna may be selectively operated.-v 1 a Still another object of my invention is toprovide a construction of beam antenna wherein a multiplicityof reradiator elements may be supported adjacent an antenna in such manner that the position thereof. may be. readily changed for selectively fixing thedirection in which'th'e antenna is effective. o

Afurther object of myinvention is to provide a construction of beam antenna which may have the directionalcharacteristic thereof selectively adjusted by altering the positionof reradiat-- hereinafter following by reference to the accom panying drawing, in which:

Fig. 1 is a perspective view 'of the beam antenna systemof my invention; Fig. 2 isa fragmentary View showing one methodwhich I employ for removably supporting the reradiator elemerits of the beam antennasystem; and Fig. 3 is a theoretical View illustrating the position of the reradiator conductors forselectively fixing the directional characteristics of the antenna.

The beam antenna system of my invention has been developed for use in thedirectio'nal signaling systemset forth more fully in; my application No. 70,162, .filed'July- 23, 1930. The beam antenna of my invention is adapted for both transmission and reception directionally. For

purposes of explaining the construction of the antenna system of my inventionv I shall describe the beam antenna particularly in connection with a transmission system. g

The beam antenna of my invention requires 5 only four rigid supporting-members for the er'ecistics. of the antenna. l /ly invention contemmade to more nearlyapproach-a circle.

at intervals with insulators. The mast 2 is suittion of the beam antenna for the longestjwaves likely to be used. Heretofore it has been proposed toerect large etructureswhich are actually shifted on a car running uponrails forthe purposev or" changing the directional character-- plates the erection of rigid supports without the necessity of erecting-a system of railsand mounting the antenna upon a moving car structure operative upon such rails. The dire'ctivity' of the beam antenna of my invention is controlled by amultiplicity of reradiator elementswhich are disposed in a portionjof a cylindrical envelope surrounding the antenna conductor, The. reradiator elements are removable from one p0 sition to another about the antenna conductor for selectively fixing the directional characteristicsof the antenna. I e Referring to the drawing in more detail, the four rigid supports employed in the beam antenna system of my invention are shown in the formof masts erected'at 1, 2, 3 and 4 in'the ground. I provide means for supporting a'substantially circular frame member 5 between masts l and.2.f A similar frame member is supported between masts 3 and 4 'as represented at 6 The frame members 5 and 6 may be formed-from wire or rope suspended in substantially cylindrical contour as shown. This is accomplished by means of the guys or stays 'Z and S extending from the opposite mastsand connected to a mul tiplicity of points about the frame members as p shown. By providing a substantial network of guys or stays '7 and 8 between masts 1 and 2 andv masts 3 and 4, the shape'oi frames 5 and 6 is I The stays 7 connect with the frame 5 tending to stretch frame 5 in a substantially circular shape.

Similarly the stays 8 extendingfrom masts 3 and 4 suspend the frame 6 in a substantially circular shape and by increasing the number of such stays the shape is made to more-nearly approach a circle. The mast 1 is maintained in a vertical position by guys represented at la suitably broken f 1 ands! pass for raising the antenna conductor 12 in substantially horizontal position. The antenna conductor is insulated at opposite ends as indicated. Leads 15 and '16 connect with the antenna conductor 12 and lead downwardly to the coupling inductance 17 which is coupled. with inductance 18 leading to the circuit of the signaling apparatus 20.

In the arrangement illustrated the antenna is connected as a doublet for transmission of signal-- ing energy. Other forms of connection between the antenna and the signaling apparatusmay be employed if desired. The reradiator elementsare adapted to be hoisted into position at selected intervals around the frame members 5 and 6. I have indicated the reradiator elements at 21, 22, 23, 24, 25, 26, 2'7, 28 and 29. Each reradiator element is constituted by ahorizontally disposed conductor extending parallel to the antenna conductor 12. The reradiator elements are all adapted to be individually andremovably mounted between the frame members 5 and 6 by halyards passing over pulleys and insulatingly connected with the ends of the .reradiator elements. The reradiator element 21 is connected to insulators 21a at eachend thereof. The halyards 2117 are connected to the end of each of the insulators adjacent the remote ends. of the re'radiator. element 21 as shown more clearly inFig. 2. The pulley 22a is secured to frame member 5 by means'of clamp 30. .A similar arrangement is provided at the op.- posite end of the antenna system so that each 'reradiator element may be readily hoisted into position or removed from position for installation in another angular position with respect to the antenna conductor. For this purpose halya'rds are provided for each of the reradiator elements represented at 2217,2325, 24b, 25b, 26b, 27b, 28b and 29b. Pulleys of the kind illustrated at 22a in Fig. 2 may be mounted at each point of intersection of l the stays 7 with the frame member 5, and at each point of intersection of the stays 8 with frame member 6 as I have represented at 31, 32, 33, 34, 35, 36 and 3'? with respect to frame member 5, and at 38, 39, 40, 41,42, 43 and 44 with respect to frame member 6. Such an installation facilitates the. removal of a reradiator element from onev position, and the installation of such a reradiator element in another position according to the direction at which the signaling energy is to be propagated as represented in the several examples indicated at Fig. 3. In Fig. 3, the antenna condoctor is represented at 12 and the arrow extending therefrom serves to indicate the direction of propagation of the signaling energy due to the effect of the reradiator elements upon the antenna conductor.

The dimensions of the antenna system of my invention depend upon the frequency at which the system must operate. The minimum dimension indicated at A is substantially one half ofthe longest radio wave length for which the screen is designed. I have found it convenient to make dimension D substantially equal to A. Dimension Bshould preferably be greatenough to permit the radiated beam to clear nearby objects such as buildings, etc., which might otherwise deflect the beam. The overall length of the antenna and screen in a horizontal direction is indicated by the dimension E.

While I have shown the antenna erected upon a horizontal axis, it will be understood that the antenna may be mounted on avertical axis with the screen surrounding the antenna conductor and the directivity of the antenna controlled by movable changing the positions of the rei'adiator elements. It will be observed that the antenna structure of my invention differs radically from beam antenna systems heretofore employed in that I provide an arrangement for shifting the individual reradiator elements constituting the screen, whereas heretofore elaborate structures have been required for shifting the entire mass of a reflector adjacent the antenna conductor.

The antenna system of my invention has proven highly practical in its construction and successful in' its operation, and while I have described my invention in one of its preferred embodiments, I desire that it be understood that modifications may be made and that no limitations upon my invention are intended other than are imposed by the scope of the appended claims.

The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposeswithout the payment of any royalties thereon. i

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. A directive antenna system comprising supporting means, a pair of substantially circular frame members carried by said supporting means, an antenna conductor extending axially of said frame members, pulley devices secured at spaced intervals around each of said circular frame members and a multiplicity of independently reconductors insulatingly suspended through said'pulley devices between said frame members, from each endthereof for controlling the directive signaling properties of said antenna conductor. I

2. A directive antenna system comprising supporting means erected at spaced intervals, sub stantially circular frames carried by said supporting means, pulley'devices secured at spaced intervals around each of said circular frames in alignment with each other an antenna conductor extending axially of said substantially circular frames, and a plurality of independently-removable auxiliary conductors suspended by said pulley devices and disposedvaround the peripheries of said substantially circular, frames equidistant from said antenna conductor, for controlling the directive signaling properties of said antenna conductor.

3. A directive antenna system comprising supporting means erected at spaced intervals, substantially circular frames carried by said supporting means and disposed in substantially vertical planes-parallel one to another, pulley devices mounted at spaced intervals around said circular frames an antenna conductor extendingaxially between said frames in substantially horizontal direction, and a plurality of independently removable auxiliary conductors individually suspended by said pulley devices as elements of a circular cylinder defined by said circular frames and insulated one from another, for controlling the directional properties of said antenna conductor.

4. A directive antenna system comprising supporting means erected at spaced intervals, a pair of substantially circular frames carried by said supporting means, a plurality of pulley devices secured at spaced intervals in similar positions around each of said circular frames, a plurality of independent reflecting conductor elements, a plurality of halyards equal in number to twice the number of reflecting conductor elemembers disposed at spaced intervals in corre ment's, each of said reflecting conductor elements being supported at each end by one of said hal yards, each of said halyards passing through and being supported by a corresponding one ofsaid pulley devices, whereby any of said reflecting conporting means, an antenna element extending axially of said circular frames and normal to the planes thereof, apluralityof wireattachment antenna element.

spending positions around each of said circular frames, a plurality of wire elements, each of said wire elements being connected at opposite ends thereof to the wire attachment members on said circular'frames at spaced intervals one withrespect to the other around said circular frames,

and means for selectively mounting orremoving said wire elements from said wire attachment i members for selectively fixing the direction'iof propagation of electromagnetic waves from said JENNINGS B. DOW.