US2045987A

US2045987A - Directional aerial system

Info

Publication number: US2045987A
Application number: US701419A
Authority: US
Inventors: Green Ernest
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1933-02-23
Filing date: 1933-12-08
Publication date: 1936-06-30
Anticipated expiration: 1953-06-30
Also published as: FR768779A; GB415141A; NL38549C; DE619026C

Description

' June 30), 11938.

E. GREEN DIRECTIONAL AERIAL SYSTEM Filed Dec. 8, 1933 2 Sheets-Sheet l INVENTOR ERNEST GREEN ATTORNEY June 3m, 1936. E GREEN 2,045,987

DIRECTIONAL AERIAL SYSTEM Filed Dec. 8, 1933 2 Sheets-Sheet 2 @D A A A A 7\ A A A T o o-'-@ c c c I L 0 0 I L (3:?) IE1 (at {"1 o I 0 G O /O O E 1 A i O C O 0 T a A Z J INVENTOR o 0 o O O ERNEST GREEN ATTORNEY Patented June 30, 1936 UNITED STATES PATENT OFFICE DIRECTIONAL AERIAL SYSTEM Application December 8, 1933, Serial No. 701,419 In Great Britain February 23, 1933 14 Claims.

This invention relates to directional aerial systems and has for its object to provide an improved and simplified form of aerial system suitable for use as a so-called beam aerial, i. e. an

aerial adapted to radiate a directional beam of radiation.

The invention is particularly adapted for use on short waves in order to provide a short wave directional beam aerial.

According to this invention a directional aerial comprises a plurality of radiating elements and a plurality of feeder elements the radiating elements extending substantially at right angles to the feeder elements and the whole system being constituted by two wires or conductors joined together at one end, each of said wires or conductors being arranged symmetrically with relation to the other and in such manner that in portions of said wires or conductors the currents substantially add their efiects so that these said portions constitute radiating elements while the currents in the other portions substantially neutralize their efiects so that these other portions constitute feeder elements.

The invention is illustrated in the accompanying drawings, Figures 1 to '7 of which show various arrangements in accordance therewith.

Referring to Figure 1 of the drawings, there is shown an aerial system which comprises two WiresUTSRQPONMLKandABC DE F G H I J K joined together at K and arranged as shown in the said Figure 1 upon which figure are marked the various dimensions in terms of wave length. It will be noticed that with the exception of the portions L K, J K, all the elements are effectively each one half the working wave length long, and the stationary wave distribution of current obtained when the whole system is excited as indicated by voltage applied between the terminals U A will be as shown in conventional manner by the broken lines in Figure 1. The currents in BC, DC, QP, OP, HI,

JI, LM, NM, GF, EF, RS, TS, are in phase, so

that these portions constitute the radiating elements while the current in AB being in opposite phase to that in UT and the current DE being in opposite phase to that of RQ and. the current in ON being in opposite phase to that of GH and the current in JK being in opposite phase to that in LK, these elements constitute feeder elements. The direction of maximum radiation will, of 'course, be perpendicular to the general plane in which the whole system lies, i. e., this system is a broadside system.

A plurality of aerial systems, as illustrated in Figure 1, may be mounted side by side, as illustrated in Figure 2 which shows two such systems, insulated tension wires TI being provided for suspension purposes.

Arrangements as illustrated in Figure 1 are, of course, bi-directional but uni-directional qualities can be obtained in manner well known, per se, by providing a suitable reflector or curtain system which may consist of a second system similar to the main aerial system and suitably tuned or independently excited.

Again, a suitable reflector may be constituted by an ordinary arrangement well known per se, of half Wave elements and in either case the reflector should be positioned approximately a quarter of the working wave length behind the aerial system. Where a plurality of systems, as illustrated in Figure 1 are employed in combination, for example as illustrated in Figure 2, they should, of course, all be energized in phase and this is accomplished in Figure 2 by utilizing a single feeding source.

Figures 3 and 4 show a slight modification of the system illustrated in Figure 1, and it is thought that the nature of this modification will be obvious from the figures in question. If an aerial system as shown in Figures 3 or 4 be excited by a voltage across the terminals S and A the current distribution will be as shown in Figure 3, the members BC, DC, EF, GF, HI, JI, JK, LK, MN, ON, PQ, RQ, constituting the radiating members and the remaining elements constituting the feeder members. Assuming that the aerial is mounted vertically, radiation will be horizontally polarized, and its main direction will be perpendicular to the general plane of the system.

If, however, the terminals S and A be connected together and energized by voltage applied between them and earth, as shown in Figure 4, a difierent current distribution as indicated in Figure 4 will be obtained and the elements AB, SR, DE, PO, GH and ML will constitute the radiating elements, the currents in the remaining elements being mutually cancelling in their efiects. In this case, therefore, assuming the aerial system to be vertical, the radiation will be vertically polarized.

By employing a voltage supply arrangement as illustrated in Figure 5 it is possible to employ an aerial system as shown in Figures 3 or 4 to radiate horizontally and vertically polarized waves independently. Activation of the aerial system for radiating horizontally polarized energy is obtained by energy delivered by the secondary WX of a transformer whose primary is energized from a suitable source I, the secondary being connected between the points S A. Activation for V ,the aerial for vertically polarized voltage applied by means of a transformer whose primary is energized from a suitable source 2 and whose secondary Z is connected between the center of WX and earth. 7

Since the systems in accordance with this invention are obviouslyutilizable either for radle ation or reception, aerials as shown in Figures 3 and 4 may be employedto receive vertically polarized waves and horizontally polarized waves independently, and such aerialsare therefore ad- .vantageously applicable to so-called diversity tion withasystem as shown in Figures 3, 4 'or'5,

' whetherzthe system is. employed for horizontal or vertical polarized radiation or both. If it be desired to radiate only horizontally or only vertically polarized waves a simple curtain ef half wave :length parallel tuned elements will constixtute a 'quite satisfactory reflector for either case,

and theseelements may be considerably less than ,aihalf'w'ave length apart.

Having "now particularly described and ascer- -tained"the"nature of my said invention and in what manner the same is to be'performed, I declare that what -Ifclaim is:

1. A directional. aerial comprising aplurality of radiating elements and a:p1uralityjof feeder elements the radiating eiements extending substantially at right angles to the feeder elements :and the Whole system being constituted by two conductorsjoineditogether :at one end, each of .said conductors being arranged symmetrically withrelation to the other and in such manner that in portionsof said conductors the currents substantially add their eifects so that these said 7 portions constitute radiating-elements while the currents in the other portions substantially neutralize their effects "so that these other portions constitute feeder elements, the two conductors :heingarranged to proceed from one'e'nd parallel to one another for a distance. of substantially a half wave length, then turn each through a rightangleand proceed away from one another for a distance approximately equal to a half wave length, then turn each through two right angles and proceed towards one another for a distance approximately equal to a half wave length, then turn each througha 'further'right angleand proceed .in the original direction for 'a distance substantially equal to a half wave length,thetwoconductors being crossed over in this portiomthen turn each through a right angle and proceed away from one another for a dis- ;tancefiapproximatelyeqnal-to ahalf wave length,

and-so on, successive portions'of each conductor,

.excepttheend portion where the twoconductors join together, :being approximately a half wave length long, the .length -of. said "end portion being substantially ronequarter .of the Working wave and the whole system. being constituted by two 7 conductors joined together at one end, each of said conductors being arranged symmetrically V with relation to the other and in such manner that in portions of said conductors the currents substantially add. their effects so that these said portions constitute radiating elements While the currents'in they-other portions substantially neutralize their effects so, that these other portions constitute feeder elements. the two conductors being arrangedtoproceed from one end parallel to one another for a distance of substantially a half wavelength, turn each through a right angle and proceed away from one another for a dis tance of approximately a quarter wave length, turn each through two right angles and proceed towards :one another for'a distance of approxi= mately one "quarter of a wave length, turn each through aright angle and proceed in the original direction for :a distance of substantially a half wave length and so on.

3. In combination with an aerial as ciaimed in claim 2, a transmitter orzrecei'ver connected between earth and the first'mentioned ends of the two conductors.

4. The combination with an aerial as defined in claim 12, of an energytran'sferring system consisting of a coil connected to the'te'rminals of said aerial, a second coil connected between the electrical center of said first mentioned coil and earth, athird-coil coupled to the first coil and a fourth coil coupled to the second coil, the two last mentioned coils being each adapted to be connected to high frequency apparatus. f

'5. A broadside antenna system comprising a pairaof closely spaced parallel horizontals other. similar pairs 01 parallel horizontals, each hori-V zontal comprising two 'co linear portions, each portionbeing hot'substa ntially longer than onehalf wave length,;each:pair being separated'from the adjacent pair by 'a vertical "distance approxirhately one-half wave length, each co-linear-portion or each horizontal "being a'radiating element and being connected at one end to the parallel colinear :portion of the same'pair .at its adjacent 7 end, intermediate substantially'verti'cal elements one-half wave length llong for conveying energy from the 'radiatingelementsnof one horizontal to those of another, the last-mentioned vertical elementsbeingpositioned withrespectto each other so as to neutralize radiation therefrom, and means iforaenergizingthesystem, whereby all horizontals are activatediin-phase;

6. A system-as definedin claim 5 characterized V in this, that :each c'o-linear pcrtion of each horizontal "comprises ;a conductor one-quarter wave I length long.

7. A system as defined in claim 5 characterized in this, that each 'co-iine'arportion of each horizontal comprises a conductor one-half wave length long, and includinga V shaped element,

' radiating elements and a plurality of feeder elements, theradiating elements'extending substantiallyat' right angles to the feeder elements and the whole system being constituted .by'two conductors joined together ;at cm end, each of said conductors being arranged symmetrically with relation to the other and in such manner that in portions of said conductors the currents substantially add their eifects so that these said portions constitute radiating elements while the currents in the other portions substantially neutralize their effects so that these other portions constitute feeder elements, the two conductors being arranged to proceed from one end parallel to one another for a distance of substantially a half wave length, then turn each through a right angle and proceed away from one another for a distance approximately equal to a half wave length, then turn each through two right angles and proceed towards one another for a distance approximately equal to a half wave length, then turn each through a further right angle and proceed in the original direction for a distance substantially equal to a half wave length, the two conductors being crossed over in this portion, then turn each through a right angle and proceed away from one another for a distance approximately equal to a half wave length, and so on, successive portions of each conductor, except the end portion where the two conductors join together, being approximately a half wave length long, the length of said end portions being substantially one quarter of the working wave length, and a similarly constructed aerial mounted side by side with said first aerial in a substantially vertical plane, both of said aerials being connected in parallel to a common transmitter or receiver.

9. A plurality of aerials in accordance with claim 8, including suspension means comprising insulated tension wires mechanically connecting adjacent ends of the radiating portions of the individual aerials.

10. An aerial in accordance with claim 1, including high frequency translating apparatus connected between the first mentioned ends of said conductors.

11. The combination with an aerial as defined in claim 1, of a reflector aerial consisting of a network of half wave length wires.

12. In an antenna system, a plurality of pairs of parallel horizontals, each horizontal comprising two co-linear portions, each pair being separated from the adjacent pair by a vertical distance approximately one-half wave length, each co-linear portion of each horizontal being a radiating element and being connected at one end to the parallel co-linear portion of the same pair at its adjacent end, intermediate substantially vertical elements one-half wave length long for conveying energy from the radiating elements of one horizontal of a pair to those of another horizontal of an adjacent pair, the last mentioned vertical elements being crossed over with respect to each other so as to neutralize radiation therefrom and to provide in phase energy to the horizontals, and means for energizing the system.

13. A broadside antenna system comprising a pair of closely spaced parallel horizontals, other similar pairs of parallel horizontals, each horizontal comprising two co-linear half wave length portions, each pair being separated from the adjacent pair by a vertical distance approximately one-half wave length, each co-linear portion of each horizontal being a radiating element and being connected at one end to the parallel 00- linear portion of the same pair at its adjacent end, intermediate substantially vertical elements one-half wave length long for conveying energy from the radiating elements of one horizontal to those of another horizontal of an adjacent pair,

the last mentioned vertical elements being positioned with respect to each other so as to neutralize radiation therefrom, and means for energizing the system whereby all horizontals are activated in phase.

14. A broadside antenna system comprising a pair of closely spaced parallel horizontals, other similar pairs of parallel horizontals, each horizontal comprising two co-linear half wave length portions, each pair being separated from the adjacent pair by a vertical distance approximately one-half wave length, each co-linear portion of each horizontal being a radiating element and being connected at one end to the parallel colinear portion of the same pair at its adjacent end, intermediate substantially vertical elements one-half wave length long for conveying energy from the radiating elements of one horizontal to those of another horizontal of an adjacent pair, the last mentioned vertical elements being positioned with respect to each other so as to neutralize radiation therefrom, and means for energizing the system whereby all horizontals are activated in phase, and a U shaped element, the legs of which are one-quarter wave length long, on top of said antenna for connecting together the two colinear conductors of the topmost horizontal.

ERNEST GREEN.