US2638545A - Radio antenna - Google Patents

Description

y 1953 w. H. DE PEAU ET AL 2,638,545

' RADIO ANTENNA Filed y 7 2 5 Sheets-Sheet 1 IN VEN TORS M4 4 //9/7 H. de PEA a H/be/e Y /1- P I/5R0 Y May 12, 1953 w. H. DE PEAU ET AL RADIO ANTENNA 3 Sheets-Sheet 2 Filed May '7, 1952 INVENTORS W4 A 04/1 4 2/ 154 0 ATTORNEY y 1953 w. H. DE PEAU ET AL 2,638,545

RADIO ANTENNA Filed May 7, 1952 5 Sheets-Sheet 5 ATTUR/Vf) Patented May 12, 1953 2,638,545 RADIO ANTENNA WilliamHDdPeau and Harry Pome'loy, Harrisllnn'g, Pa.

AppIication May Z'I, 1952, Serial No.l286,540

This invention relates to radio antenna'e for transmitting or receiving radiant energy, "and "more particularly to an'an'tenn'a for use in the V. H. F. and U. H. 1". 'bands. I I

An object is to provide a high gain antenna of the above type which responds efficiently to waves over a comparatively wide range of "frequencies.

Another object is to provide a novel'and improved antenna which is suitable for various uses in'V. H. F. and U. H. F. signalling, suchas radar,

microwave, television and FM broadcast hands or the like.

proved antenna which isparticu'larly effectivein fringe areas where signal strength is weak.

Another object is to provide an antenna having improved characteristics.

Other objects and'advantages will be apparent as the nature of 'theinvention is more "fully-disclosed.

The ideal antenna for fringe areas'should'work efficicnt'l'y'on 'all channels,-shoulcl keep noise pick 'up to a minimum, should'be directiveso *as to minimize co' chan'nel interference when such is present; and should he light in weight, mechanically strong, and easy to build 'a-n'insta'll.

'In accordance with the present invention these results are attained'hy providing a =clinear pattern made up of units, each of 'Which' has aplurality of resonant frequencies. Theknnits e'ac'h comprise four legs with ends joined to form-a diamond, and aJplural-ity of such units are j oined to for'm fthe colinear pattern. .The assembly is light" in weight, sturdy, and offers low wind res'is't'aihce.

Each leg of each nnit is 'designed'to resonate ata'defiriitefrequency. -Th'e combinationofifour legs in the diamond-shaped unit also has a res'onant iirequency, Ea'ch' two legs taken together have a resonant frequency and the distance be- "tweenfoppos'ite points, that #is the vertical :and horizontal oliagona'l distances, provide still other resonant frequ'encies.

iclosed diamond structure is self-.zphas- -ing. Thatris, the voltages in :theitwoadjacent legs at 'any'corner are :in phase. Hence a plurality of such :units can she -coupled.. .at adjacent oornersnwithout the use of stubs, -capacitors,

transformers, resistors, coils, or other coupling devices.

20(innate. (o1. 250 33.57)

ifrequency. 'between..the points A5 and 2E, and at A series of such diamond-shaped units are joined in "colinear"relationship to "form a dipole which is fed from a pair of unconnected-adjacent points of the center diamond elements. I

The units .mayfbe of different sizes to resonate at "differentirequenci'esand 'the legs of any unit may "'be of the same length "or of different lengths, depending upon the characteristics desired.

The nature of the "invention will befbet'ter understood "from the following description, taken iirconnection with the accompanying drawings, in which specific embodiments have been shown for purposes of illustration.

In the drawings: Fig. '1 is a "schematic diagramcf an antenna according to the invention having two pairsof diamond grid units arranged as a dipole;

Fig. 2 is 'a schematic diagram of an antenna having "two series of colinear diamond g-r id series; I

Fig. '3 is a schematic diagram similar to Fig. 2 showing a further embodiment of the invention; Fig. "4 is "a schematic diagram similar to Fig. 2 showing -a further embodiment; 1

Fig. '5 isan isometricview of an antenna showing "the constructual arrangement of the =lements; and

Figs. -6 -and "7 are schematicwiews similar to Figs. 2 and '3 s'how ing still "further embodiments of the invention.

Referring to the drawings, a .four ...grid \dipole is shown in The dipole comprises :a pair ofi-nner grids Hi, formedloy four legs ll'l,-:l2,

-13, 1-"4 joined electrically and mechanically at c'orners ill, "l6, H, I B to form diamond-shaped grids, and .a' pair of outer grids 20 formed by four legs 2|, 22, 2%, 24 joined electrically and mechanicallyat corners :Ifl, .25, :28, .23? toiorm diamond-shaped grids. The :inner andqonter grids are thus joined at Ail the points 15 -constitute the .feed or take-01f points. I .Leads. 30

'are connecte'd to"the points t5 and connect to the receiver or transmitter. .7 1

This adiamond gricl :dipole will resonate at one half of. that :frequency- :along the path 2 6 1 15., 11, I16, 1:5 Each leg resonates :at a =definite irequency, :each pair of ;legs :at one-half of the latter frequency, ;and the gpath around thedour legs of .:each gridrat a-stilllower frequency. 'The :grids. alsov resonate at frequencies determinedby the distances 15-4! and theidistances. ,l fi -lfi;

Hence by expanding 0ne-0f the distances .lt s--lll,

lie-l8, and 1 decreasing the other distance, .various bandf'characteristics can be obtained.

The legs are preferably made of small diameter conductors so as to reduce the end effect and to reduce weight. If large diameter legs are used, the length is decreased slightly to compensate for the end effect due to the capacitive action across the apexes of the diamonds.

In Fig. 2 a double dipole diamond grid is shown. The assembly consists of pairs of upper grids 35, 36 and .pairs of lower grids 31, 38 formed each by four legs 39, 40, 4|, 42. The legs 39 are joined at points 43, 44, 45, 46. The legs 40 are joined at points 41, 48, 49 and 45, the grids 35 and 36 being joined at 45. The legs 4| are joined at points 50, 52, 53 and the legs 42 are joined at points 52, 49, 54 and 55, the grid 38 being joined to the grid 36 at point 49 and to the grid 31 at point 52. Points 43 and 50 are commected by a leg 56 and the leads 51 are taken from the midpoints of the legs 56.

In this embodiment the legs 39 and 4| are shorter than the legs 40 and 42, the distance 44-46 is less than the distance 41-48 and the distance 43-45 is equal to the distance 45-48.

The legs 39 and 4| have a higher resonant frequency than the legs 40, 42 and the grids 35, 31 have a higher circumferential resonance than the grids 36, 38. However, since the horizontal length (43-45) is the same as that of the grids 36, 38, the inner grids 35, 31 act as horizontal extensions to the outer grids 36, 38 on the lower frequencies, giving the overall effect of one large id or dipole.

Phasing between inner and outer grids and upper and lower grids takes place automatically at the points or apexes. Hence the grids can be joined directly, as shown, without coupling devices.

The assembly is mounted Vertically and is directional in the normal to the plane of the assembly. The maximum radiation is broadside to the :plane of the elements and is also bi-directional.

The legs may be one-fourth or one-half wave length in length or a sub-multiple, such as oneeighth Wave length, depending upon the available space and the frequency band with which the antenna is designed to operate.

The sensitivity to horizontally r vertically polarized Waves can be accentuated as desired by properly combining the grids. For example, if a plurality of grids are combined colinearly in a horizontal plane, the overall assembly would be most sensitive to horizontally polarized Waves resonating to a dipole of the same overall length. However, each grid will have its own resonant frequency in addition to contributing to the overall length of the longer dipole.

The picking off (or feeding) of the dipole at closed points, as indicated, instead of opening the grid at such points, takes advantage of the automatic phasing of a closed grid and eliminates the coupling elements which would otherwise be required.

The electrical characteristics can be altered bymaking the legs of unequal length, i. e. by making the top legs longer or shorter than the bottom legs, or by making the right hand legs longer or shorter than the left hand legs, or by making the four legs of unequal length.

The addition of the second row of grids (upper or lower) increases the impedance to a value approximately equal to that of a standard lead-in.

The points 46 and 5| are shown as not connected electrically. This produces separate resonant circuits which enhances the broad band 4 characteristic of the assembly. These points could be connected to decrease the band width, but increase the directivity characteristics.

A reflector can also be used to increase further the directivity. The reflector may constitute the tubing used to support the assembly, or a curtain type or diamond grid reflector can be used. If diamond grids are used, they would correspond in dimension to the front antenna and would be insulated at all points except the center which may be grounded to the pole.

Fig. 3 illustrates an antenna similar to Fig. 2 and has been given similar reference characters with the suffix a. In Fig. 3 the grids 35a and 31a are of less horizontal width and greater vertical height than the grids 35, 31 of Fig. 2 and the adjacent points 46a, 5 la. are joined. In this form the band width is somewhat less than the form of Fig. 2 and the other-characteristics are varied accordingly.

A further embodiment is shown in Fig. 4 wherein the parts corresponding to those of Fig. 2 have been given similar reference characters with the sumx b. In Fig. 4, however, all the legs of each grid are of different lengths and the points 46b and 5|b are joined by a diamond grid 50 having legs 6 This grid introduces additional resonant frequencies and further broadens the band width to which the antenna responds.

Fig. 5 shows a practical installation of the antenna of Fig. 2. The antenna elements have been identified by the same reference characters. In this embodiment the points 43, 45 and 48 are mounted on insulators 63, 65, 68 carried by pins 64, 66, 68 from a horizontal tube 10 and the points 50, 52, 54 are mounted on insulators 12, 14, 16 carried on pins 13, 15, 11 from a horizontal metal tube 18. The horizontal tubes 15 and 18 are carried by a vertical pipe 19. The points 46 and 5| are joined mechanically, but not electrically by an insulator 80.

In this form the horizontal tubes 10 and 18 constitute a reflector although a second diamond grid assembly may be mounted on the other side of the tubes 10 and 18 and grounded thereto at the center if desired.

The smaller grids have been shown in Figs. 2, 3 and 4 as on the inside (center) of the dipole. They may, however, be disposed on the outside and a plurality of small grids may be connected in series. The small grids may be of the same or of difierent sizes, as shown in Fig. 6. Furthermore, although the smaller grid resonates at a higher frequency than the larger grid it does not reduce appreciably the pick-up efficiency of the larger grids. The inside grids serve as transmission lines for the adjacent outside grids.

In Fig. 6 larger grids Illa, similar to the grids ID of Fig. 1, are disposed on the inside of the dipole and smaller grids 20a and 30a. are disposed on the outside. The grids 20a and 30a are of different horizontal widths. The arrangement is otherwise similar to that above described.

Fig. '7 shows a multiple dipole arrangement having three sets of colinear grids comprising inner grids I02), I00, id and outer grids 20b, 20c, 20d arranged generally as in Fig. 3 with adjacent points joined. In Fig. 7 the lead may be connected to any pair of adjacent center points and the effect can be Varied by connecting one or both of the other pairs together or by connecting the center points of each side together.

Obviously the number of grid sections and their arrangement may be varied according to the effect desired.

What is claimed is:

l. A broad band antenna comprising at least two grid units, each unit including at least two elements having four conductor legs joined at their ends to form a closed diamond-shaped grid structure having four apexes, the elements forming each of said units being disposed colinearly in the same plane with their diagonals in horizontal alignment to form a series of elements having an apex at each end and having adjacent end apexes of successive elements electrically connected, and a lead connected to each of said units, each of said leads being connected to one of said end apexes of a unit.

2. An antenna, as set forth in claim 1,'in which said grids have legs of equal length.

3. An antenna, as set forth in claim 1, in which the units are each equilateral and the legs of one unit are of different lengths than the legs of another unit.

4. A broad band antenna comprising a plurality of grid units, each unit having four conductor legs joined at their ends to form a closed diamond-shaped grid structure having four apexes, said units being disposed colinearly in the same plane with theirdiagonals in horizontal alignment, said units extending symmetrically on both sides of a center to form a pair of series of grids, adjacent apexes of successive units on each series of grids being electrically connected, the adjacent center apexes of the two series of grids being electrically insulated from each other, and a pair of leads connected to said last mentioned apexes.

5. An antenna, as set forth in claim 4, in which the legs of said units are of equal length.

6. An antenna, as set forth in claim 4, in which each unit is equilateral and the legs of one unit of each series are of a different length than the legs of another unit of each series.

7. An antenna, as set forth in claim 4, in which the legs of the unit of each series adjacent the center of the antenna are shorter than the legs of the unit adjacent thereto.

8. An antenna, as set forth in claim 4, in which the legs of the various units of each series are all of different lengths.

9. An antenna, as set forth in claim 4, having two units in each series, the center units being smaller than the outer units.

10. A broad band antenna comprising a plurality of grid units arranged in parallel series, each unit having four conductor legs joined at their ends to form a closed diamond-shaped grid structure having four apexes, the units all being disposed in the same plane, the units of each series being disposed colinearly with their diagonals in horizontal alignment, each series being separated at the center into right and left groups, the adjacent apexes of successive units of each group being electrically connected, the adjacent apexes of at least one pair of corresponding units in the adjacent series being electrically connected, the adjacent center apexes of the said right and left groups being electrically insulated,

the center apexes of the respective right and left groups of adjacent series being electrically connected by conductors, and leads connected to said last conductors.

11. An antenna, as set forth in claim 10, in which all units are equilateral and have legs of equal length.

12. An antenna, as set forth in claim 10, in which all units are equilateral but the legs of the center units of each group are shorter than the legs of the adjacent units of each group.

13. An antenna, as set forth in claim 10, in which the legs of the different units are of unequal length.

14. An antenna, as set forth in claim 10, in which the center unit of each group is smaller than the adjacent unit, and the adjacent apexes of the smaller units of the respective series are spaced, and a diamond-shaped grid unit connects said last apexes.

15. In an antenna, as set forth in claim 10, conducting tubes supporting the units of each series and insulated therefrom, a pipe carrying said tubes and forming therewith a reflector grid to enhance the directional effect of said antenna.

16. An antenna, as set forth in claim 10, in which the outer units of each group are smaller than the center units thereof.

17. An antenna, as set forth in claim 10, in which each group includes a large unit and a pair of smaller units.

18. An antenna, as set forth in claim 17, in which the smaller units are located on the outside and the larger units at the center.

19. An antenna, as set forth in claim 18, in which the units of each group all have different horizontal lengths.

'20. A broad band antenna comprising a plurality of grid units arranged in parallel series, each unit having four conductor legs joined at their ends to form a closed diamond-shaped grid structure having four apexes, the units all being disposed in the same plane, the units of each series being disposed colinearly with their diagonals in horizontal alignment, each series being separated at the center into right and left groups, the adjacent apexes of successive units of each group being electrically connected, the adjacent apexes of at least one pair of corresponding units in the adjacent series being electrically connected, and leads connected to adjacent center apexes of one pair of said groups.

WILLIAM H. DE PEAU. HARRY M. POMEROY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,366,195 Kondoian Jan. 2, 1945 2,615,005 White Oct. 21, 1952 FOREIGN PATENTS Number Country Date 974,560 France Oct. 4, 1950

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