US2813268A

US2813268A - Foldable high gain antenna system

Info

Publication number: US2813268A
Application number: US445260A
Authority: US
Inventors: Joseph V Fisher
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-07-23
Filing date: 1954-07-23
Publication date: 1957-11-12
Anticipated expiration: 1974-11-12

Description

Nov. 12, 1957 J. V. FISHER FOLDABLE HIGH GAIN ANTENNA SYSTEM 5 Sheets-Sheet l Filed July 23' 1954 dans-PH u. -syse 4 7- rae/sys A N N E T N A N I A G VH .G I H E L B A D .L O F Nov. 12, 1957 m www W qw ,U1 w f Q5/W@ Eknlllll-IIIII.

` NVENTOR.

BY l Y .Nov. 12, 1957 .1.v. FISHER FOLDABLE HIGH GAIN ANTENNA SYSTEM 5 Sheets-Sheet 3 Filed July 23, 1954 JNVENTOR.

owe-PH u. -/sf/sfe,

United States Patent `FoiooAnipn HIGH GAIN ANTENNA SYSTEM i Joseph V. Fisher, Pittsburgh, Pa. `Ammannati July z3, 1954, serial No. 445,260 7 Claims. (Ci. 343-915) This invention relates to antennas, and more particularly to an improved wide band antenna suitable for reception of television channels and for FM reception.

A main object of the invention is to provide a novel and improved wide band antenna for television and FM, said antenna being simple in construction, involving a minimum of electrical and mechanical parts, providing high gain, and being foldable to a relatively compact size for transportation or storage.

A further object of the invention is to provide an improved multiple bay high gain wide band antenna of the type employing `a reflector screen, said antenna being inexpensive to fabricate, being rugged in construction, involving `substantially no corrosive joints, and which is easily adjustable, particularly with reference to ultra high frequency channels, so that a desired sharpness of the ultra high frequency field pattern may be obtained by adjusting the antenna. t

A still further object `of the invention is to provide an improved multiple bay high gain, wide band antenna array which employs a reflector screen of the lattice type, the improved antenna array being foldable to a rela tively compact size` for transportation or storage, the improved antenna array involving relatively simple components, being easy to setup for use, and providing eiiicient reception of television and FM signals. i

A still further object of the invention is to provide an improved wide band, .high gain antenna of the type employing a reflector screen of the lattice type, said antenna being neat in appearance, being relatively light in weight, and being arranged so that only one transmission line is required over the entire spectrum received by the antenna.

, Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure 1 is a perspective view of a two-bay antenna constructed in accordance with the present invention, `shown set up for use.

Figure 2 is an enlarged cross sectional detail view taken on the line 2-2 of Figure l.

Figure 3 is an enlarged cross sectional detail view taken on the line 3 3 of Figure 1.

' Figure 4 is a perspective view of a modified form of antenna constructed in accordance with the present invention. i

Figure 5 is an enlarged fragmentary side elevational view of the antenna shown in Figure 4.

Figure 6 is a rear elevational view of a further modified form of antenna constructed in accordance with the present invention.

Figure 7 is a fragmentary rear elevational view of a still further modication of antenna according to the present invention.

Figure 8 is an enlarged cross sectional detail view taken on the line 8 3 of Figure 7.

Referring to the drawings, `and more particularly to ,Figures 1,12 and 3, 1-1 designates one form of improved 2,813,268 Patented Nov. l2, 1957 antenna according to the present invention. The antenna 11 is of the multiple bay typeand may comprise, for example, two bays stacked one above the other and supported on a vertical mast 12, the respective bays being designated at 13 and 14. The top bay 135 comprises a straight reiiector bar 17 of conductive material, for example, of aluminum tubing, and a pair of dipole elements designated at 18, 18, each dipole element comprising a conductive rod of aluminum or similar material, formed at an intermediate portion thereof with a U-shaped, relatively narrow loop of substantial length, shown at 19.

Respective insulators

20, 20 rigidly connect the bight portions of the

loops

19, 19 to the reiiector bar 17, the loops 19 being symmetrically located on opposite sides of the mid point of the reflector bar 17. The mid point of the reflector oar 17 is connected by a rigid bracket rod 21 to an insulator 22, the inner ends of the respective dipole elements 1S, 18 being secured to the opposite ends of the insulator 22.

The outer portions of the respective dipole elements 1S, 1t; are subsatntially V-shaped, as shown at 23, 23, facing away from the reflector bar 17. Respective rigid connecting rods 24, Z4 connect the reflector bar 17 to insulators 2S secured to the ends of the V-shaped portions 23 of the dipoles.

As is clearly shown in Figure 1, the inner portions 26 of the respective dipoles are inclined inwardly toward reflector bars 17 and together define a V-shaped conguration similar to the configurations of the respective outer J -

shaped dipole portions

23, 23.

All the elements thus far described, comprising `the reiiector bars 17, the dipoles 18, 1S, the

respective loops

19, 19, and the bracket elements 24, 24 and 21 are in the same horizontal plane.

The reflector bars 17 may be of a length suitable for the television channels to be received, for example, may be of a length substantially equal to one-half the wave length of the mid channel of thelower portion of the television spectrum, namely, the spectrum including channels 2 to 6. The distance between the outer ends of the

dipoles

18, 13 may be substantially equal to the length of the reflector bar, namely, to one-half thewave length of the mid channel ofthe lower portion of the television spectrum.

The lengths of the V-

shaped portions

23, 23 and the V element defined by the

inner ends

26, 26 of the dipoles are substantially equal andcorrespond to onehalf of the Wave length of a particular frequency, for example, a frequency substantially in the middle of the upper V. H. F. television band, namely, the portion of the television spectrum including channels 7 to 13. Obviously, since the length of the V-

shaped portions

23, 23 andthe V-shaped portion defined by the

inner portions

26, 26 of the dipoles are equal, each of the V-shaped elements thus defined has a length approximately onethird that of the reflector bar 17 The spacing of the main portions of 'the

dipole elef ments

18, 13 from the reflector bar 17 is, of course, determined by the lengths of the bracketbars 24, 24, 21 and the

1oops

19, 1 9. In a typical embodiment of the invention, this length was approximately equal to a quarter wave length of a middle channel in the upper portion of the V. H. F. television spectrum, namely, that portion of the television spectrum including the channels 7 to 13.

Obviously, a considerable range ofdimensions may be employed in choosing the proper lengths of the reflector bar 17 and the

dipole elements

18, 18. For example, the retiector bar 17 may be of a length equal to the length of one-half of the wave length for the lowest television channel of the spectrumto be covered and the lengths of the V-

shaped portions

23, 23, as well as the intermediate V-shaped portion defined by the

inner end elements

25, 26 of the dipoles may be in accordance with the wave length of a particular channel in the upper portion of the V. H. F. television band, namely, in the band including channels 7 to 13, the spacing ofthe dipole elements 4from the reflector bar being similarly governed by the selected upper V. H. F. channel frequency and the spacing being one-quarter of the wave length of said selected frequency.

l The inner ends of the dipoles of the bays 13 and 14 are connected by a pair of vertical harness conductors 27 and 28. A suitable insulator 31 connects the intermediate portions of the harness conductors 27 and 28, suitable terminals 50 and j51 being provided at the intermediate portions of said harness conductors to which a transmission line may be connected, or which may be employed for interconnecting the antenna bays 13 and 14 with another pair of antenna bays to provide a four-bay array.

Designated at 38 and 40 are a pair of relatively small, ultra-high frequency tuning loops which are adjustably mounted on the upper portions of the harness conductors 27 and 28 and which are provided with suitable means 'for securing the loops in adjusted positions on said harness conductor upper portions. A similar pair of relatively

small tuning loops

38 and 40 are adjustably mounted on the lower portions of the harness conductors 27 and 28 and are also provided with suitable means for securing said loops in adjusted positions on said lower portions. The

tuning loops

38, 40, 38 and 40 are angularly adjustable with respect to the conductors 27 and 28 and are also adjustable vertically, whereby a desired tuning of the array to ultra high frequency channels may be obtained. Since the

bow loop elements

38, 40, 38 and 40 are angularly adjustable as well as rotatable, they can be set at any desired angle so as to adjust the sharpness of the U. H. F. eld pattern of reception.

The bracket rods 21, extending perpendicularly from the mid point of the respective reflector rods 17 are electrically connected to said reflector rods, forming a part thereof, and serve to keep out side signals, making the antenna array sharply directional. Similarly, the rod elements 24, 24 are electrically connected to the reector bars 17, for the same purpose. An important feature of the construction of the reflector bays 13 and 14 is that the U-shaped elements 19 act lnot only as matching stubs but also take the place of the supporting rods and phasing harnesses employed in previously known antenna arrays.

The respective bays 13 and 14 may be separated by a desired Vertical spacing which is, of course, related to the signal wave lengths to be received. For example, the vertical spacing between the bays 13 and 14 may be such that with respect to the lower portion of the V. H. F. television spectrum, the vertical spacing between the bays is equal to one-fifth of a wave length, for example, onefth of the mid Wave length in this portion of the band, or, alternatively, one-fifth of the lowest wave length in the band.

Designated respectively at 52 and 53 are respective rellector screen sections of the lattice type which are hingedly connected respectively to the

reflector bars

17 and 17 at 54 and 55. Each reilector screen section may comprise a pair of oppositely directed wires bent to form generally V-shaped elements 56, the wires being connected at their meeting bend portions 57, as by loop brackets 58 engaged around the bend portions 57, said loop brackets 58 being provided with overlapping apertured lug portions 59 which are connected by fastening bolts 60. The clamping bolts 60 also serve to fasten the ends of respective supporting straps 61 surrounding the associated

reflector bar

17 or 17 to thereby secure the screen section to the reflector bar by means of the associated bolt 60. A wing `nut 61 is provided'on the vend of the bolt, allowing the bolt .to be readily loosened when the assembly is to be taken apart or folded.

The bend portions of the lower wire of the upper section 52 and the bend portions of the upper wire ofthe lower screen section 53 are hingedly connected together at 65 in the manner shown in Figure 3. Thus, the bend portions of the lower wire of the upper screen section, designated at 66 are received in looped straps 67, and the bend portions of the upper wire of the lower screen section, designated at 68 Aare received in similar looped straps 69. The looped Straps 67 and 69 have apertured

lug portions

70 and 71 which are overlapped and through which extend the fastening bolts 72 which are provided with' the wing nuts 73. Thus, the screen may be at times folded on a horizontal axis located substantially midway between the reflector bars 17 and r17 to bring the reector bars and their associated pairs of dipole elements adjacent to each other (the harness conductors 27 and 28 being, of course, removed) whereby the antenna array may be collapsed to a relatively compact size for transportation or storage. In installing the antenna, the reflector Abars 17 and 17 are merely separated to their correct spacing, causing the screen to be stretched to its proper, substantially coplanar condition, whereupon the wing nuts 73 maybe tightened to lock the screen in `its coplanar condition. The harness conductors 27 and 28 may then be connected to the antenna array in the manner shown in Figure 1, and the array may then be fastened to the supporting mast 12, as by the conventional brackets and 80.

.In the modified form of the antenna shown in Figure 4, the screen comprises a pair of lattice sections and 91, each lattice section comprising a plurality of spaced parallel conductive rods 92 which are rigidly connected to spaced vertical conductive rods 93, the rods 93 of the upper lattice section being connected at their lower ends r to the top ends of the rods 93 of the lower lattice section as by bolts 94 which are aligned on an axis substantially midway between the rellector bars 17 and 17 and which serve as hinge connections for the lattice sections when the bolts 94 are loosened. The bolts 94 are, of course, provided with wing .nuts 95 which may be tightened to lock the lattice sections 90 and 91 in coplanar relationship, as shown in Figure 4. The intermediate portions of the respective vertical bars 93 are secured to the respective reflector bars 17 and 17' by fastening straps 96 which are provided with apertured lugs 97 clamped to the bars 93 by fastening bolts 98, as shown in Figure 5.

In the form of the invention shown in Figure 6, the upper and lower reflector screen sections are designated respectively at 101 and 102 and are generally .similar in construction to the

screen sections

52 and 53 of Figure -1 except that the wires of the `screen sections .ane formed with arcuately bowed bends 103 instead of having V- bends. The adjacent bends 103 are secured to the respective reflector bars 17 land 17' by fastening brackets 104, said brackets comprising straps which embrace the reflector bars 17 `and 17 and which are provided with suitable loops in .which the arcuate wire bends are fastened.

The depending arcuate bends of the lower wire of the upper screen 101 are connected to the upstanding arcuate bends of the upper wire of the lower screen section 102 by

respective straps

67 and 69, and fastening bolts 72 provided with wing nuts 73, as in Figures 1 and 3, defining hinge connections which are aligned along a line midway between the reector bars 17 and 17', allowing the reflector screen to be folded when the wing `nuts 73 are loosened. The connections 104 may be similar to the corresponding connections employed at 54 and 55 in Figure 1, and illustrated in detail in Figure 2.

In the form of the invention shown in Figures 7 and 8, the rellector screen comprises an upper lattice section and-a lower lattice section 111, .the upper lattice section being secured to the upper reflector bar 17 and the ,lower `lattice .section being secured to the lower re- 75 ector bar 17'. Each .lattice section comprises a pair of wires or

rods

112 and 113 bent to define successive alternating V elements, the V elements of the

wires

12 and 13 being superimposed and being connected b-y bolts or other suitable `fasteners at their intermediate portions, as shown at 114. As shown in Figure 8, the overlapping portions of the wires or

rods

112 and 113 are flattened, as shown at 115 and 116, and overlie the reflector rods 17 and 17', the fastening bolts 114 extending through the reflector rods and through the flattened

portions

115 and 116 of the lattice rods, each bolt 114 being provided with a fastening nut 118. The lowermost ends of the lattice rods of the upper reflector screen section 110 are connected to the uppermost bends of the lattice rods of the lowermost screen section 111 by

respective straps

67 and 69 having overlapping apertured lug portions connected by fastening bolts 72 provided with wing nuts 73, as illustrated in detail in Figure 3 and as employed in connection with the embodiment of the invention shown in Figure l. The connections of the upper lattice section 110 with the lower lattice section 111 are along a line spaced midway between the reflector bars 17 and 17', whereby the reflector screen may be folded to a collapsed position by loosening the wing nuts 73 as in the previously described forms of the invention.

`lt will be noted that each structural element of the array in each of the forms of the invention specifically described above has an electrical function, and that a minimum amount of mechanical parts are thus required in order to complete the antenna assembly. This not only reduces the cost of the assembly but also considerably lightens its weight, making it easier to erect the antenna andl rotate the same to obtain the desired orientation. The lightness of the antenna also makes it suitable for use with antenna rotating mechanisms of the conventional type.

While certain specific embodiments of an improved antenna has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

l. In an antenna of the character described, a pair of horizontal parallel reflector bars, respective pairs of dipole elements rigidly connected to and electrically associated with ysaid reflector bars in spaced substantially parallel relation thereto, each pair of dipole elements being entirely in the same horizontal plane as one of said reflector bars, respective lattice-like reflector screen sections hingedly secured to the respective reflector bars, and means hingedly connecting said screen sections on a horizontal axis parallel to and located between said reflector bars, whereby the antenna may be at times folded to bring the reilector bars and their associated pairs of dipole elements adjacent to and parallel to each other.

2. ln an antenna of the character described, a pair of horizontal parallel reflector bars, respective pairs of dipole elements rigidly connected to and electrically associated with said reflected bars in spaced substantially parallel relation thereto, each pair of dipole elements being entirely in the same horizontal plane as one of said reflector bars, respective lattice-like reflector screen sections hinged to the respective reflector bars, means hingedly connecting the bottom of the upper screen section to the top of the lower screen section on a horizontal axis parallel to and located between said reflector bars, each dipole element comprising a conductor rod formed at an intermediate portion thereof with a matching stub comprising a U-shaped, relatively narrow loop of substantial length, and respective insulators rigidly connecting the bight portions of said loops to the associated reilector bars, said dipole elements being spaced symmetrically relative to the mid points of their associated reflector bars.

i 3. In an antenna of the character described, a pair of horizontal parallel reflector bars, respective pairs of dipole elements rigidly connected to and electrically associated with said reflector bars in spaced. substantially parallel relation thereto, each pair of dipole elements being entirely in the same horizontal plane as one of said reflector bars, respective lattice-like reflector screen sections hinged to the respective reflector bars, means hingedly connecting the bottom of the upper screen section to the top of the lower screen `section on a horizontal axis parallel to and located between said reflector bars, each dipole element comprising a conductor rod formed at an intermediate portion thereof with a matching stub comprising a U-shaped, relatively narrow loop of substantial length, and respective insulators rigidly connecting the bight portions of said loops to the associated reflector bar, said dipole elements being spaced symmetrically relative tothe mid points of their associated reflector bars, the arm portion of each dipole element located outwardly of its loop being substantially V-shaped and facing away from its associated reflector bar.

4, In an antenna of the character described, a pair of horizontal parallel reflector bars, respective pairs of dipole elements rigidly connected to and electrically associated with said reflector bars in `spaced substantially parallel relation thereto, each pair of dipole elements being entirely in the same horizontal plane as one of said rellector bars, respective lattice-like reilector screen Sections hinged to the respective reflector bars, means hingedly connecting the bottom of the upper screen section of the top of the lower screen section on a horizontal axis parallel to and Vlocated between said reflector bars, each dipole element comprising a conductor rod formed at an intermediate portion thereof with a matching stub comprising a U-shaped, relatively narrow loop of substantial length, respective insulators rigidly connecting the bight portions of said loops to the associated reilector bar, said dipole elements being spaced symmetrically relative to the mid points of their associated reflector bars, the arm portion of each dipole element located outwardly of its loop being substantially V-shaped and facing away from its associated reflector bar, the arm portion of each dipole element located inwardly of its loop being inclined inwardly toward its associated reflector bar, and respective vertical harness conductors connecting the ends of the inner arm portions of the dipole elements.

5. In an antenna of the character described, a pair of horizontal parallel reflector bars, respective pairs of dipole elements rigidly connected to and electrically associated with said reflector bars in spaced substantially parallel relation thereto, each pair of dipole elements being entirely in the same horizontal plane as one of said reflector bars, respective lattice-like reflector screen sections hinged to the respective reflector bars, means hingedly connecting the bottom of the upper screen section to the top of the lower screen section on a horizontal axis parallel to and located between said reflector bars, each dipole element comprising a conductor rod formed at an intermediate portion thereof with a matching stub comprising a U-shaped relatively narrow loop of substantial length, respective insulators rigidly connecting the bight portions of said loops to the associated reflector bar, said dipole elements being spaced symmetrically relative to the mid points of their associated reflector bars, the arm portion of each dipole element located outwardly of its loop being substantially V-shaped and facing away from its associated reflector bar, the anm portion of each dipole element located inwardlly of its loop being inclined inwardly toward its associated reflector bar, respective vertical harness conductors connecting the ends of the inner arm portions of the dipole elements, and a relatively small, closed conductor loop element mounted on each harness conductor.

6. ln au antenna of the character described, a pair of horizontal, parallel reflector bars, respective pairs of dipole. elements rigidly connected to and electrically associlated with said reflector bars in spaced substantially parallel relation thereto, each pair of dipole elements being entirely' in the same horizontal plane as one of said reector bars, respective, lattice-like reector screen sections hinged toA the respective reilector bars, means hingedly connecting the bottom of the upper screen section to theV top of the lower screen section on a horizontal axis parallel to-` and, located midway between said reflector bars, each dipole element comprising a conductor rod formed at an intermediate portion thereof with a matching stub comprising a U-shaped relatively narrow loop .of substantial length, respective insulators rigidly connecting the bight portions of said loops to the associated relector bar said dipole elements being spaced symmetricallytrclative to the mid points of their associated reector bars the arm portion of each dipole element located outwardly of its loop being substantially V-shaped and facing away from its associated reector bar, the arm portion of each dipole element located inwardly of its loop being inclined inwardly toward -its associated reflector bar, respective insulators rigidly connecting the ends of the inner arm portions of the respective pairs of dipole elements, and respective horizontal transverse conductive support elements connecting said last-named insulators to the mid points of the respective reflector bars.

7. In an antenna of the character described, a pair of parallel reflector bars, respective pairs of dipole elements rigidly connected to and electrically associated with said reector bars in spacedv substantially parallel relation thereto, each pair of dipole elements being entirely in the same horizontal plane as one of said reilector bars, respective lattice-like reflector screen sections hinged to the respective reflector bars, means hingedly connecting the bottom of the upper screen section to the top of the lower screen, section on. a horizontal axis parallel to and locatedy midway between said reector bars, each dipole element comprisingl a` conductor rod formed at an intermedia-te portion thereof with armatching stub cornprising a U-shaped, relatively narrow loop of substantial length, respective insulators rigidly connecting the bight portions of said loops to the associated reflector bar, said dipolel elements being spaced symmetrically relative to thernid points of their associated reector bars, the `arm portion-.of each dipole element located outwardly of its loop being'z substantially V-shaped and facing away from it-s associated reflector bar, the arm portion of each dipole element located inwardly of its loop being inclined inwardly towards its associated reflector bar, respectivc vertical; harness conductors connecting, the ends of the inner anm portions of the dipole elements, respective insulators rigidly connecting the ends of the inner arm portions of the respective pairs of dipole elements, respective horizontal transverse conductive support elements connecting said last-named insulators to the mid points of the respective retlector bars and being electrically connected to said reflector bars, respective additional insulators connected to the bends of the V-shaped outer arm portions, and respective additional horizontal transverse conductive support elements connecting said last-named additional insulators to the respective reector bars and being electrically connected to said reilcctor bars.

References Cited in the tile of this patent UNITED STATES. PATENTS 2,270,314 Kraus Jan. 20, 1942 2,586,276 UmStead Feb. 19,l 1952 2,655,599 Finncburgh m Oct. 13, 1953