US2945233A - High frequency antenna with laminated reflector - Google Patents

Description

July 12, 1960 wl EI'AL 2,945,233

HIGH FREQUENCY ANTENNA WITH LAMINATED REFLECTOR Filed Jan. 26, 1954 2 Sheets-Sheet 1 FIG.\

Robert L. Williston 4 INVENTORS ATTGRNEY July 12, 1960 N. R. WILD ETAL HIGH FREQUENCY ANTENNA WITH LAMINATED REFLECTOR Filed Jan. 26, 1954 2 Sheets-Sheet 2 Norman R. Wild INVENTORS Robert L. Williston ATTORNEY I 'HIGH FREQUENCY ANTENNA WITH LAMINATED REFLECTOR Norman R. Wild, Hollis, and Robert L. Williston, Milford, N.H., assignors, by mesne assignments, to Sanders Associates, Incorporated, Nashua, N.H., a corporation of Delaware I Filed Jan. 26, 1954, Ser. No. 406,134

4 Claims. (Cl. 3*43840) This invention relates to directive antenna systems for ''the radiation and reception of high frequency electro- "ma'gnetic energy waves. tion relates to antennas employing a paraboloid reflecto More particularly, this invento {obtain directivity as used in radar.

ln'conventional search techniques the antenna is typically oscillated toscan a desired area. The rate of oscillation and the efliciency' of radiation has, in the past, been limited by the weight and strength of the paraboloid reflector and the error introduced by deformation of the thereto and held with supporting rods.

It is an object of this invention to provide an improved antenna with a reflector in the form of a precise paraboloid;

It is a further object of this invention to provide an improved antenna with a paraboloid reflector having a mounting surface precisely located with respect to the axis of the paraboloid; and

It is a still further object of this invention to provide an improved antenna with a paraboloid reflector that is strong, light weight, economical to manufacture and will retain its precise construction under extremely adverse environmental conditions.

Other and further objects of this invention will be apparent from the following description of a typical embodiment thereof, taken in connection with the accom-' panying drawings.

States Patent 2,945,233 Patented July 1251 960 "ice,

2 V frequency energy is coupled through a transmission line 6 which is supported by mounting bracket 7 in contact with'the paraboloid reflector 2. Mounting holes 8 permit assembly of the antenna to asupporting structure. As shown in Fig. 4, the paraboloid 2 is constructed of va series of layers of glass cloth or Fibreglass sheets-10 to form resin-impregnated, supporting sheets vas will be further described below. 'Wire screen 11 provides the reflector. The support 9 is surrounded by a foam plastic 12 (such as alkyd-isocyanate available, e.g., under the trade name Lockfoam. as manufactured by Napco Chemical Company of Harrison-New Jersey). A portion of the foam plastic has been cutaway to expose the larger than the outer diameter of the support rod. The

support rod is threaded as at:15 and inserted into the oversized hole. A round nut 16is threaded on to the support rod4.- An epoxy resin 19, such as Hysol "6020 as v manufactured by HoughtonLaboratories, :Inc:, of Clean,

In-accordance with this invention there is provided an antenna comprising successive layers of resin impregnated glass cloth and a conductive reflecting member. An antenna carrying metallic supporting web is disposed between the layers and behind the reflecting member and a foam resin is used to bind them all together to form a composite paraboloid reflector. A radiator is centered by the web and mechanically connected thereto by a plurality of supporting rods.

In the accompanying drawings:

Fig. 1 is a three-dimensional perspective view of an antenna embodying this invention;

Fig. 2 is a side view of the antenna of Fig. 1;

Fig. 3 is a three-dimensional perspective view of the paraboloid reflector of the antenna of Fig. 1;

Fig. 4 is an exploded view of the elements of the paraboloid of the antenna of Fig. l; and

Fig. 5 is an enlarged cross-sectional view of a portion of the antenna, illustrating a supporting rod assembly.

Referring now in more detail to the drawings, in Fig. 1 a radiator 1 is shown mounted on a paraboloid reflector 2. The radiator is supported at one end by mounting cap 3 and support rods 4. The support rods are assembled to the paraboloid reflector 2 at the junctions 5. High the paraboloid.

New York, is poured into the. space'provided between the support and 4 and the support 9. The mounting nut 16.is

counter-bored and drilled to permit insertion of the set The use of this technique for securing the support rods precludes distortion of the paraboloid andenables the radiator to be assembled-very accurately on the axis 'of The parabolcidlis assembled in a three-stepmolding process. The inside laminate of the paraboloid is formed by means of a vacuum'bag technique on the surface of the convex part of the mold. Two sheets of glass cloth 10 are placed on the convex mold piece, covered by a sheet of wire screening 11 and followed by another sheet of glass cloth 10, and laminated together with the use of an alkyd polyester resin commercially available as Selectron 5003 as manufactured by Pittsburgh Plate Glass Company, Pittsburgh, Pennsylvania. The outside laminate is formed on the concave portion of the mold and consists of two glass cloth sheets 10 laminated together with the alkyd polyester resin. The support 9 is placed on the concave mold and the foaming resin is poured in and the mold is closed. After .a suitable curing period, the mold is opened and the paraboloid removed. The use of poly-tetra-fluoro-ethylene, available under the trade name of Teflon as manufactured by E. I. du Pont de Nemours & Company, covering the surfaces of the mold and operating as a mold release permits ready removal of the paraboloid.

A number. of techniques are available for providing a v conductive reflecting surface. In addition to the use of mosphere.

The antenna embodying this invention is of light weight, sturdy construction and can be manufactured with great facility and economy.

While there has been hereinbefore described What is at present considered a preferred embodiment of the invention, it will be apparent that many and various changes and modifications may be made with respect to the embodiment illustrated without departing from the spirit of the invention. It will be understood, therefore, that all those changes and modifications as fall fairly within the scope of the present invention, as defined in" the appended claims, are to be considered as a part of the present invention.

What is claimed is: h

1. A composite parabolic antenna comprising in combination successive parabolic layers of resin-impregnated,

glass- 01mb; a parabolic conductive reflecting member; a

metallic supporting web adapted to .carry .an .antenna and having a substantial part thereof disposed between said layers of glass cloth and behind said reflecting member; a rfi'oam :resin ibinding'together :said layers :of :glass nlnth, said deflecting member and said metallic web: to frinm :a composite parabolic reflector; .a radiator secured :to'iand accurately :centeved day :said metallic :Wfib; "and a plurality of supporting "rods mechanically connecting said mediatortosaid metallicweb.

2. A composite panabolic antenna-comprising tin nomibinationsuccessive parabolic layers of resin-impregnated, glass cloth; a parabolic conductive reflectingmember; a nnetalIic supporting web member acarrying ;an antenna eradiat'or; :a foam binding ltogether said :layers of glass .cloth, :said 'reflecting member and said metallic "web member 'to :form an integral one-piece parabolic reflector; a plurality of radiator supporting rods -c9nmected-to and extending from :saidradiator to said metallic web member; :and plastic means joining said rods and said metallic web. I r v .3. Acomposite parabolic antenna comprising in com- :bination successive parabolic layers of resin-impregnated, glass cloth; .a parabolic conductive reflecting member; at metallicsupponting webhaving an annular central part .adapted to receive-ran antenna radiator -.with :qeadrant-l-y :disposed :menibcrs extending therefrom and integrally :fiormed :therewith and adapted to :receive radiator support zrods, said textension members :and a substantial part of composite parabolic reflector; a radiatorsecured to said :tcentral-part and accurately centered :by said metallic web;

four supporting rods mechanically connecting said radiator 10 said members, each of .said rods extending through over-size threaded orifices in its respective extension member and having a threaded portion within said orifices; a threaded retainer having an outer diameter greater than the diametenoj said orifices secured to the threaded portions of each of said rods; and a plastic resin securing said rod and retainer .10 said W51? to enable strain free assembly of said rolds to said web without further adjustment. 7

4. ,A composite parabolic antenna reflector comprising, in combination: successive parabolic layersof -Iesinirnpregnated, glass cloth; a parabolic, metallic screen reflecting member; a generally concave, metallic, supporting web, having an annular central part adapted to receive an antenna device with quadrant-1y disposed members extending therefrom and integrally formed therewith and adapted to receive said quadrantly disposed members of .said antenna tdevice, said 'web and a substantial part of the annular :central part thereof :being disposed between said layers .of said glass cloth and behind said metallic screen reflecting :member; and a foam resin binding together said layers of glass cloth, :said reflecting :member and said metallic web-tn :fonm saidcomnnsitezrefiectnir.

V 'Refetencgs file-drill i fi1c-of his patent ,i

UNITED STATES PATENTI S Brueker May 22, 1956 UNITED TSTAITESPATENTOFFICE CERTIFICATE OF CORRECTIQN Patent No. 2 945238 July 12 1960 Norman Wild et a1,

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, 'line 2, before "members" insert extension Signed and sealed this 16th day of January 1962..

( SEA L) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents

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