US2027020A - Directional antenna - Google Patents

Description

Jan. 7,1936; R CARTER -2,02 7,o2o

DIRECTIONAL ANTENNA Filed Sept. 15, 195 52 4 Sheets-Sheet l VA'ITORNE'Y mm 24 I {V I I I I PIIV ENTORER JW 5 HQM Jan. 7, 1936.

P. s. CARTER 2,027,020 DIRECTIONAL ANTENNA Filed Sept. .15, 1932 4 Sheets-Sheet 2 151 676 0/ UPPER W/Ri FREQUENCY [EA/67H 0F 4/5 /1847 05 (0/1 57? WIRE INVENTOR P. 5. CA TER BY WOL/ 7, 1936. p, s, CARTER 2,027,020

DIRECTIONAL ANTENNA Filed. Sept. 1 1952 4 Sheets-Sheet 3 0. INVENTOR P. 5. CA 1 R BY f v x ATTORNEY Jan. 7, 1936. P; s. CARTER DIRECTIONAL ANTENNA Filed Sept. 15, 1952 4 Sheets-She et 4 INVENTOR P. 5. CAR! ER ATTORNEY Patented Jan. 7, 1936 UNITED STATES PATENT OFFICE DIRECTIONAL ANTENNA Philip S. Carter, Port Jefferson, N. Y., assignoi' to Radio Corporation of America, a corporation of Delaware Application September 15, 1932, serial No. 633,229

28 Claims.

radiate energy directively. This arrangement comprises a pair of linear conductors which are long relative to the length-of the communication wave and disposed at 'an angle in such a manner that when energized radiation occurs principally along the bisector of the angle. Such a V type antenna, it has been found, has a bidirectional characteristic radiating equally well in two directions-namely, toward the diverging 5 ends of the conductors, and toward the converging ends of the conductors.

I Heretoiore, in order to obtain .a unidirectional characteristic it has been the practice to place a similar parallel pair of wires arranged in the same V formation mentioned, an odd number of quarter wave lengths away from the antenna properin a direction along the bisector of the angle formed by the wires. This second pair of wires is then left unenergized, or energized in 5 proper quarter phase relation such that for one direction radiation cancellation occurs whereas in the other direction there is a strengthening of the propagated electromagnetic waves.

A disadvantage inherent in the system above referred to is the necessity for providing separate supporting structures for the second set of V type conductors in order to obtain the unidirectional antenna efiect. The present invention overcomes this disadvantage and enables uni-directional radiation of electromagnetic energy without the necessity for the second set of supporting structures. Consequently, there is obtained, in accordance with the present invention, a system which is simplified in character and less expensive to construct and to maintain. As an illustration:

Heretofore a single section V type uni-directional antenna system has required, six supporting structures; the' present invention has reduced this number to only three.

Essentially, the present invention comprises a uni-directional radiating system wherein two V formations of linear'conductors, which are long relative to the length of the communication wave, are placed one above the other and energized in such a manner that the currents in the two Vs are in phase quadrature relation with respect to each other. The radiated wave leaving the lower wires is arranged to be in leading phase with respect to that leaving the upper wire by a phase angle equivalent to the spacing along the line of the desired maximum radiation, thus adding perfectly to the radiated wave leaving the upper wire. In the reverse direction, the two waves rect space relation and reflector action, the wires of .the lower V are shortened by a desired amount. The invention is described more in detail in the following description, which is accompanied by drawings, wherein 6 Figure 1 illustrates a V type antenna system embodying the principles of the present. invention; and I Figure 2a illustrates, in part, a plan view of the system of Figure 1, and Figure 2b, in part, a side view of the system 'of Figure 1, both parts being favorably arranged for a discussion of the principles involved in the present invention.

Figure 3 illustrates an arrangement differing from that of Figure 1 in that this arrangement causes the radiation from the upper and lower Vs to add best at anangle of 0 degrees to the horizon.

Figure 4 shows a system in accordance with the present invention wherein thespacing between 20 the upper and lower wires is made one quarter wave length in order to obtain simplicity in phasing.

Figure 5 shows an arrangement similar to that of Figures 1 and 2 except that the upper wires 25 are made shorter thanthe lower.

Figure 6 illustrates a system of three Vs, one above the other, in which the lower and upper units are made shorter and fed in even quadrature phase with respect to the center unit.

Figure 7 illustrates a system of four Vs, one above the other, in which each successive V is shorter than the one above.

Figure 8 illustrates a broadside system in accordance with the present invention, utilizing 35 three sections.

Figure 9 illustrates an arrangement in which both of the Vs lie in vertical planes and in which one of the two Vs is made shorter than the other. 7

Figure 10 shows an arrangement wherein two Vs lie in the same vertical plane and are carried by the same structures. 1

Figure 11 shows an arrangement of four Vs lying in horizontal planes, one above the other, and made alternately long and short, the'shorter -Vs being fed in quarter phase'relation with respect to the longer Vs. 1

Referring to Figure 1, there is shown an antenna-system adapted for uni-directional radiation of electromagnetic energy comprising an upper pair of conductors l and 2', which are made long relative to the length of the communication wave anddisposed in a horizontal plane in V formation 55 at an angle in such manner that radiation' occurs principally along the bisectdr of the angle. This angle depends upon the length of the conductors and the wave length in a manner which is fully described in my United States Patent low wires I and 2, spaced therefrom a convenient distance and mounted on the same supporting structures, are located another pair of conductors 3 and 4, also in V formation, each of the latter being respectively parallel to conductors l and 2.

In order to obtain the desired directive action,

' the lower V, comprising wires 3 and 4, is arranged so that the currents therein are in phase quadrature with respect to the currents in the upper V. One method of accomplishing this, while at the same time enabling the matching of the impedances of the transmission lines, is shown in Figure 1 wherein adjustable connection 5 enables the tuning of upper V wires I and 2 and adjustable strip 6 enables the tuning of the lower V wires 3 and 4. Connections 1, I are also arranged to be adjustable for matching the impedances of the quarter wave length jumpers 8, 3. When properly adjusted, the correct quarter wave phase relation may thus be obtained. For proper operation, the lengths of the wires extending from the ends of the conductors to corresponding positions on the upper and lower feeder pairs of the impedance matching structure, which are indicated by :c, a: in the drawings, should be made equal, although itwill be understood that the absolute lengths are immaterial.

So far, the effects of ground upon the resulting radiation have not been mentioned. In both theory and practice it has been found that the reflections from ground are such as to always result in zero radiation horizontally at the usual communication distances from any short wave antenna. It has also been found that radiation at angles in the neighborhood of 10 to the horizon is most effective at a distance receiver. -By

placing a V wire radiator at a height of one wave length above the average dry ground, maximum radiation takes place at about 10 to the horizontal. Therefore the antenna arrangement usually preferred is one in which the radiation from the lower and upper conductors adds perfectly at an angle of about 10 to the horizon and in which the mean height isof the order of one wave length.

To eliminate difllculties in adjustment caused by large mutual impedance between units, it is preferable to have the spacing between the upper and lower conductors at least one quarter wave length.

Dimensions which might be used in a typical design are as follows:

Length of upper wire=8 wave lengths Angle of maximum radiation=l0 to the horizon Effective spacing=l% wave lengths along the line inclined at 10 to the horizon in the bisecting plane.

Half angle of V==18.5

Lower conductors 3 and 4 are arranged to be shorter than upper conductors I and 2 by an amount sufficient to result in the correct space relation for reflector action. The distance between the end of the wire on the lower V and the .end of the corresponding upper wire on the upper V is made an amount such that when projected upon the line of desired maximum radiation the projection is an odd number of quarter waves. There are several ways by which this relation may be accomplished, depending upon the particular condition it is desired to fulfill.

If it isdesired that maximum addition of the radiation from the two V units take place hori-- '9 and ill in Figure 1 upon the bisecting plane with straight connections when N is odd and zontally then the following equation must he satisfied Xcos a=(2N1)-:

6 wherein X is the stagger or horizontal distance between insulators 9--I0, a the half angle of the V wires, N any integral number, and A the wave length. Such an arrangement is illustrated in Figure 2. 10

If it is desired that maximum addition of radiation takeplace at an angle 0 to the horizon, and a definite spacing S between wires 2 and 4 has been given, then the relation must be satisfied.

If a definite angle for the line d between insulators !Il0 with respect to the horizon be assigned, and it is'deslred that best addition take 20 place at the angle 0, the length of the line it may then be determined from the relation In Figure 3 is shown a system so designed that 25 the projection of the line d between the insulators of the upper and lower wires upon the plane bisecting the V wires coincides with the line of desired maximum addition of radiation. This 30 is a convenient arrangement but not necessarily better than others satisfying the relations set forth.

The projection of the line d between insulators should coincide with the line of maximum ra- 85 diation (10 to the horizon according to Figure 3). With the foregoing conditions the following relations obtain:

1.75). cos 10=d cos cos 18.5" 40 1.75). cos 10=d sin 1 from which tan =tan 10' cos 18.5" and =9.5

sin 10 sin 9.5 L842) 45 Another arrangement which has the advantage of making possible correct phasing adjustment on the antenna structure itself is shown in 50 Figure 4. In this arrangement the vertical spacing is made reversal of connections when N is even. A typical design might be:

Length of upper radiators=8 wave lengths Angle of maximum radiation=about 10 to the 50 horizon Vertical spacing=% wave length Eflective spacing along the line of maximum radiation at 10 to the horizon= wave length Half angle of V=17.5

The direction of maximum radiation may be reversed by makingthe current in the lower V lag that in the upper, assuming, of course, that the lower V wires are the shorter.

For convenience in describing this invention of the other, and means for energizing said lower (2N- 1)%+S sin 0 cos 0 cos a this being the same relation as. given previously except for a reversal of the sign before-S sin 0. Such an arrangement is shown in Figure 5.

Figure 6 shows an arrangement of three V wires wherein there are two pairs of shorter wires, one above and one below the longer V pair. This has the advantage of greater concentration of radiation vertically.

Figure 7 shows an arrangement wherein several Vs are placed one above the other, each being shorter than the one above and each fed in successive quarter phase relation.

Figure 8 shows a broadside arrangement of a number of systems placed side by side in order to increase the horizontal concentration of radiation.

The invention is not limited to systems wherein the Vs lie in horizontal planes. Any of the arrangements described may -be'rotated 90 so that the wires lie in vertical planes. The radiated wave is then polarized in a vertical plane. Figures 9 and 10 show two such arrangements.

- Any of the systems described may be adjusted for maximum radiation ,in the direction of the converging ends of the Vs rather than in the direction of the diverging ends, merely by a reversal in the polarity of the feed lines between pairs.

If desired, the systems may be used without metallic connections to the reflectors since an adjustable wire pair may readily be used for tuning with excellent results.

I claim:

1. A uni-directional antenna system comprising two pairsof diverging conductors extending substantially longitudinally in the direction of desired transmission and placed one abovethe other, the conductors of one pair having lengths different from those of the second pair, and means for energizing said pairs in phase quadrature relation with respect to each other.

2. A uni-directional antenna system comprising more than two pairs of diverging conductors extending-substantially longitudinally in the direction of desired transmission and placed one above the other, the conductors of at least one pair having lengths different from those of another pair, and means for energizing said pairs in successive quarter phase relation.

3. A uni-directional transmitting antenna system comprising two pairs of diverging conductors placed one above the other, the conductors oi. one pair having lengths difierent from those of the second pair, and means for energizing said pairs such that the waves radiated from one of them lead in phase the waves radiated from the other pair.

4. A uni-directional transmitting antenna system comprising two pairs of diverging conductors placed one above the other, the conductors of the lower of said pairs being shorter than those pair such that the waves radiated therefrom lead in phase the waves radiated from the upper of said pairs.

5. An antenna system comprising a plurality of pairs of diverging conductors arrangedin parallel planes and placed one above the other, the conductors of one of said pairs having lengths different from those of another pair, means for v energizing said pairs of conductors, and means associated with said conductors for obtaining a phase displacement in space of the waves radiated from one of said pairs with respect to the waves radiated from the other of said pairs.

6. A uni-directional antenna system comprising a pair of linear conductors angular disposed ductors located below said first pair, the conductors of said second pair being shorter" than 20 radiators in phase opposition whereby standing 30 waves of opposite instantaneous polarity are formed onthe radiators, another pair of angularly disposed linear conductors of different length spaced away from said first pair a vertical distance, said second pair of wires being energized 35 in such manner that currents therein are in phase quadrature relation in respect to the currents in the other pair.

8. A directional antenna comprising a pair of linear conductors angularly disposed with respect to each other, each conductor having a length which is long relative to the length of the communication wave at the operating frequency, means for producing standing waves thereon whereby radiant action of the antenna is'predominantly along the direction of the bisector formed by the conductors, and means for obtaining a uni-directional effect in said antenna system comprising another pair of linear conductors'angularly disposed with respect to each other and spaced away from said first pair a vertical distance substantially equal to aquarter wave length and having different lengths than the wires of said first pair.

9. A uni-directional antenna comprising a pair of linear conductors angularly disposed with respectto each other, each substantially a plurality of half wave lengths long and open ended, and means for exciting the radiators whereby radiant action of the antenna is predominantly along the direction of the bisector of the angle formed by the conductors, a second pair of linear conductors angularlyv disposed with respect to each other, and shorter than the conductors of said first pair, located below said first pair, said second pair of conductors being arranged to be energized such that the currents therein are in phase quadrature with respect to the currents in said first pair of conductors.

10. A system as defined in claim 9, characterized in this, that the currents in said second pair are in leading phase with respect to the currents in said first pair. a

11. A system as defined in claim 9, characterized in this, that said vertical spacing between said two pairs of conductors is substantially equal to a quarter wave length.

12. A uni-directional antenna system comprising two V shaped wire formations placed one above the other,each of said V formations comprising a pair of conductors angularly disposed with respect to each other, said wires having a length which is long relative to the length of the communication wave, the wires of one pair having lengths different from the wires of the other pair, and means for energizing the lower of said two V formations in such manner that the current therein is in phase quadrature with the current in the upper V formation.

13. A uni-directional antenna system comprisg ing two V formations placed one above the other, each V formation comprising a pair of wires angularly disposed with=respect to each other, each wire being long relative to the length of the communication wave, the wires of the lower V being shorter than the wires of the upper V, and

- the distance between the end of one,o1' the wires on the lower V and'the corresponding wire of the upper V being such that when projected upon the line of desired maximum radiation the projection is an odd number of quarter waves.

14. A V-type directional antenna system comprising a pair of conductors angularly disposed with respect to each other and arranged in a single plane, a second pair of conductors angularly disposed with respect to each other and parallel to said first pair of conductors and spaced therefrom a vertical distance, said second pair of wires being shorter than said first pair, means for energizing said two pairs of wires such that the currents in both pairs are in phase quadrature relation with respect-to each other, the horizontal distance between the ends of the corresponding wires of the first and second pairs being equal to where n is an integer, is the wave length, and a the half angle of the V.

15. A uni-directional transmitting antenna system comprising two pairs of diverging conductors placed one above the other, the lower of said pairs being shorter than the other, and means for energizing said lower pair such that the waves radiated therefrom lag in phase the waves radiated from the upper of said pairs.

16. A broadside antenna arrangement comprising a plurality of pairs of diverging conductors extending substantially longitudinally in the direction of desired transmission and placed one above the other, and means for energizing said pairs in successive quarter phase relation, and additional pairs of diverging conductors placed adjacent and on one side of said first pairs and similarly arranged with respect to each other to extend in the direction of desired transmission.

17. A uni-directional antenna system comprising a plurality of pairs of diverging conductors, 7 each pair comprising wires extending substantially longitudinally in a vertical plane in the direction of desired transmission and placed one above the other, and means for energizing said pairs in successive quarter phase relation.

18. A uni-directional antenna system comprising two pairs of diverging conductors extending substantially longitudinally in the direction of desired transmission and placed one above the other, the conductors of one pair having lengths different from those of the second pair, and

means for energizing said pairs in phase quadrature relation with respect to each other.

19. A v-type directional antenna system comprising a pair of conductors angularly disposed with respect to each other and arranged in a single plane, a second pair of conductors angularly disposed with respect to each other and parallel to said first pair of conductors and spaced therefrom a vertical distance, said second pair of conductors being shorter than said first pair, means for energizing said two pairs of wires such that the currents in both pairs are in phase quadrature relation with respect to each other, the horizontal distance between the endsof the corresponding wires of the first and second pairs being equal to 1 (-'.Zn l))\/4S sin cos 0 cos a where n is an integer, 'y is the wave length, a half the angle of the V, S is the spacing between the upper and the lower wires and 0 is the angle of maximum radiation to the horizon.

20, A V-type directional'antenna system comprising a pair of conductors angularly disposed (211+ 1))\/4+S sin 0 cos (9 cos a the angle of the V, S is the spacing between the upper and the lower wires and 0 is the angle of maximum radiation to the horizon.

21. A unidirectional antenna comprising a pair of' linear conductors angularly disposed with respect to each other, each substantially a plurality of half wave lengths long and open ended, and means for exciting the radiators whereby radiant action of the antenna is predominantly along the direction of the bisector of the angle formed by the conductors, a second pair of linear conductors angularly disposed with respect to each other and shorter than the conductors 01. said first pair, located above said first pair, said second pair of conductors being arranged to be energized such that the currents therein are in" phase quadrature with respect to the currents in said first pair of conductors.

22. A unidirectional antenna system comprising two pairs of diverging conductors, the corre-- 22, characterized in this, that said pairs of conductors are in the same vertical plane.

24. An antenna system in accordance with claim 22, characterized in this, that. each pair of conductors is'in a different horizontal plane.

25. A unidirectional transmitting antenna system comprising two pairs of divergingconduta I where n is an integer, 'y is the wave length, a half tors placed one above the other and located in different horizontal planes, the conductors of one pair having lengths different from those of the second pair, means for energizing said pairs such that the waves radiated from one of them lead in phase the waves radiated from the other pair, and

another similar arrangement of two pairs of diverging conductors arranged above said first two pairs, said last two pairs being also so energized that the waves from one of them lead in phase the waves radiated from the other.

26. A unidirectional antenna system compris-l ing a pair of linear conductors angularly disposed with respect to each other, each conductor having a length which is long relative to the length of-the communication wave, and two other pairs of angularly disposed linear conductors one placed above and the other below said first pair, the conductors of said first pair having A lengths which difler from the conductors of said other two pairs,

and means for energizing said upper and lower pairs in phase quadrature with respect to said first pair of conductors.

27. An antenna system in accordance with claim 26, characterized in this, that the conductors of said first pair are longer than the conductors of said other two-pairs.

.28. A directional antenna system comprising a pair of conductors angularly disposed'with respect to each other and arranged in a single plane, a second pair of conductors also angularly disposed with respect to each other and arranged in a plane parallel to said first plane but spaced away from said first plane, the wires of said second pair being shorter than the wires or said first pair, and means for energizing said pairs such that the waves radiated from one of them lead in phase the waves radiated from the other pair.

PiiIUIP s.

I Certificate of Correction Patent No. 2,027,020. A January 7, 1936.

' a PHILIP s. CARTER It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Page .2, first column, line 29, beginning with the word So strike out all to and including 1 8.5 in line 61, 'and insert the same after line 32, second column of same page; second column, line 24, strike out the formula and insert instead d cos 0 cos it cos a d sin sin 0; (2N1))\4; line 41 (last line of equation), for cos read sin; page 4, second column, lines 20and 41; claims 19-and 20 respectively, for greek letter gamma 7 read X and that the said Letters ,Patent should be read with these corrections therein thatthe same may conform to the record of the case in the Patent Office.

Signed andsealed this 28th day of April, A. D. 1936.

[SEAL] LESLIE FRAZER,

Acting Commissioner of Patents;

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