US2053658A - Directional aerial - Google Patents

Directional aerial Download PDF

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Publication number
US2053658A
US2053658A US678613A US67861333A US2053658A US 2053658 A US2053658 A US 2053658A US 678613 A US678613 A US 678613A US 67861333 A US67861333 A US 67861333A US 2053658 A US2053658 A US 2053658A
Authority
US
United States
Prior art keywords
aerial
loops
length
wave length
radiation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US678613A
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English (en)
Inventor
Franklin Charles Samuel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
RCA Corp
Original Assignee
RCA Corp
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Filing date
Publication date
Application filed by RCA Corp filed Critical RCA Corp
Application granted granted Critical
Publication of US2053658A publication Critical patent/US2053658A/en
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Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q11/00—Electrically-long antennas having dimensions more than twice the shortest operating wavelength and consisting of conductive active radiating elements
    • H01Q11/12—Resonant antennas
    • H01Q11/14—Resonant antennas with parts bent, folded, shaped or screened or with phasing impedances, to obtain desired phase relation of radiation from selected sections of the antenna or to obtain desired polarisation effect
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q11/00—Electrically-long antennas having dimensions more than twice the shortest operating wavelength and consisting of conductive active radiating elements
    • H01Q11/02—Non-resonant antennas, e.g. travelling-wave antenna
    • H01Q11/04—Non-resonant antennas, e.g. travelling-wave antenna with parts bent, folded, shaped, screened or electrically loaded to obtain desired phase relation of radiation from selected sections of the antenna
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q11/00—Electrically-long antennas having dimensions more than twice the shortest operating wavelength and consisting of conductive active radiating elements
    • H01Q11/12—Resonant antennas
    • H01Q11/14—Resonant antennas with parts bent, folded, shaped or screened or with phasing impedances, to obtain desired phase relation of radiation from selected sections of the antenna or to obtain desired polarisation effect
    • H01Q11/18—Resonant antennas with parts bent, folded, shaped or screened or with phasing impedances, to obtain desired phase relation of radiation from selected sections of the antenna or to obtain desired polarisation effect in which the selected sections are parallelly spaced

Definitions

  • This invention relates to directional aerials and more particularly to directional aerials suitable for use on short waves.
  • the invention has for its object to provide a relatively simple directional aerial system whereby sharp concentration of energy may be obtained in a desired direction with substantially no radiation in the opposite direction.
  • the direction of radiation is endwise of the aerial, i. e. in the general direction in which the aerial extends.
  • an aerial which is long relative to the working wave length is ex tended in a desired line of direction and consists of lengths of conductor arranged substantially in that line, said lengths alternating with and connecting in series lengths of conductor making an angle to the said line, the lengths relative to the working wave length and the positions of the said lengths of conductor being such that the radiation from those lengths which are at an angle to the general line of extension of the aerial is additive in one direction and substantially mutually cancelling in the opposite, while the total radiation from the remaining lengths is equal to or approximates to zero.
  • Figurevl shows, diagrammatically, one arrangement in accordance therewith, and Figure 2 shows the current distribution in two loops of the aerial of Figure 1.
  • A, B, C, D W, X, Y, Z is a directional aerial adapted to give concentrated radiation endwise and suitable for use on short waves.
  • 'I'his aerial has an over-all physical length (measured in its general line of extension) of any desired Vplurality of wave lengths, for example, four wave lengths.
  • the aerial is energized at one end from a suitable transmitter-S which is earthed at one terminal and connected at the other to one end of a feed
  • the other end of the feed line L1 is connected to the end A of the aerial and the far end Z of the aerial is preferably earthed as shown through a second line L2 in series with a resistance R oi value substantially equal to the surge im- .pedance of the said aerial.
  • Waves will travel along the aerial from A to Z, but owing to the termination of the said aerial by an impedance equal to its surge impedance, there will be no reiiection of energy back from Z to A.
  • the said aerial Starting from the transmitter end of the aerial (the end A) the said aerial comprises a portion AB extending at right angles to the general line of (Cl. Z50- 11) by a fourth portion D E which extends in the genlo eral line of extension of the aerial and is onequarter of a wave length long less the length of the second portion, i. e., the portion DE will be 1/sth of a wave length long if BC is 1/20th of a wave length.
  • the fifth portion E F of the aerial l5 is parallel and similar to the first portion AB; the sixth portion F G corresponds to the second portion B C; the seventh portion G H to the third portion CD and the eighth portion HI to the fourth portion DE and so on.
  • the length AB CD forms a iirst loop extending at right angles to the general line of aerial extension
  • the length E F G H forms a second loop
  • the length I J K L a third loop
  • these loops being connected in series by the portions DE, HI and LW which are in the same straight line and extend in the general line of aerial extension.
  • each loop consists approximately of one half wave length of wire bent back vupon itself the loops being spaced substantially one quarter of a .wave length apart.
  • each loop AB CD, E F G H, and so on acts like a quarter wave aerial.
  • the phase at the pointA is some 270 in advance of that at the pointE so that the phase of radiation from the successive loops A B C D, E F G H will differ by 270.
  • the radiation from the loops is additive in thegeneral direction ZA and mutually cancelling in the opposite direction' AZ.
  • the dimensions A B in the accompanying drawing be termed the depth of a loop, the dimension B C plus D E the spacing between loops, and the dimension BC the Width of a loop.
  • the wires AB and C D are straight so that if the length measured along the wire AB is a quarter of a wave length the depth of the loop is physically a quarter of a wave length.
  • the wires A B and C D may be folded so that the physical depth of the loop will be less than the length measured along the wires A B or C D."
  • the width of the loop is not critical and need only be sufficient to ensure that the wires AB and CD do not make contact; in fact the wire BC can be dispensed with altogether and the points B and C united into one point if the loop be made in the form of a V having its apex at the common point B C.
  • the polar curve of radiation is a somewhat flat nosed unidirectional curve point in the direction ZA.
  • the sharpness of the polar curve may be increased.
  • the current decreases along the aerial principally due to radiation and if the physical length A to Z is some four wave lengths, then the current at Z- is, in practice, generally less than one-tenth the current at A and in these circumstances, therefore, the terminating line L2 and surge resistance R may be dispensed with without appreciably affecting the polar curve.
  • Figure 2 illustrates the current distribution in two loops of the aerial, in four relative phases differing successively by degrees.
  • the current distribution isshown with loops A B C D and E F G H pulled out straight. Attenuation is neglected and it is assumed that the wave travels from A to H and passes on.
  • the effective currents in the loops A B C D and E F G H when folded up these currents being obtained by summing up the currents in A B C D and E F G H at that instant, remembering that C D and G H are reversed by the change of direction of the wire.
  • the effective currents in the loops A B C D and E F G H are identical with the current distribution in a one-quarter wave earthed aerial and that they act as such. Also that as the Y phase in E F G H is 270 degrees behind A B C D the effective currents combine in the direction H A.
  • Aerials in accordance with this invention may generally be employed for harmonies or a fundamental frequency wave, but in general the directional characteristics are different for dierent harmonics.
  • the present invention provides a comparatively simple and efficient uni-directional aerial giving a high degree of concentration and not requiring a reflector.
  • the degree of concentration is, of course, a function of the aerial length (measured in the direction of extension) in terms of the wave length.
  • the illustrated construction be modified by adding a complete wave length of wire to the total length of wire in the first four portions and a complete wave length to the total length in the second four portions and so on, still maintaining the physical distance between the beginning of the first portion and the end of the fourth, the beginning of the fifth and the end of the eighth and so on, at one quarter of the working wave length, concentrated radiation will again be obtained in the general direction of extension and away from the transmitter end.
  • This addition of one wave length of wire to each group of four consecutive portions presents, however, the advantage that as the length of each loop may be made longer, stronger radiation per loop may be obtained if desired.
  • the decrement along the wire will be greater and the useful effective length of the aerial (measured in the general direction of extension) will be reduced so that the concentration will not be so great.
  • the loops may be arranged at some angle other than 90 to the general direction of extension, for example at 60 thereto and if this be done then, by suitably adjusting the length of the fourth, eighth, twelfth portions of the aerial (and so on) concentration can be obtained along a line making a desired angle with the general direction of extension.
  • 'I'his effect enables the unit aerial to be constructed in such manner that lt may be readily supported from a single mast and, if desired, a plurality of such unidirectional 'aerials may be accommodated from a single mast.
  • a plurality of aerials in accordance with the present invention may be employed in combination to obtain improved concentration if desired.
  • An endwise aerial which is, from end to end, at least approximately four times the length of the working wave length and which consists of a continuous conductor bent to form loops at intervals along the conductor, said loops being at an angle to the direction of radiation which is the general direction of extension of the aerial, said loops having an overall length approximately equal to a one-half wave length and being separated from one another by lengths of conductor approximately equal to one-quarter of a wave length.
  • An endwise extended aerial consisting of a plurality of conductive portions in the same straight line and in the line of extension of the aerial, each of said conductive portions being substantially one-quarter of a wave length less 5% measured along the conductor, said portions being connected in series by loops at an angle to the line of extension, each of said loops being substantially half a wave length long less 5% measured along the conductor, the physical length of said aerial from end to end being at least approximately four wave lengths.
  • An endwise extended aerial consisting of a plurality of conductive portions in the same straight line and in the line of extension of the aerial, each of said conductive portions being substantially one-quarter of a wave length less 5% measured along the conductor, said portions being connected in series by loops at an angle to the line of extension, each of said loops being substantially half a Wave length long less 5% measured along the conductor, a terminating resistance connected to one end of the aerial and a source of radio frequency energy connected to the other end of the aerial.
  • An endwise aerial which is long relative to the working wave length and which consists of a continuous conductor bent to form loops at intervals along the conductor, said loops. being at an angle to the direction of radiation which is the general direction of extension of the aerial, said loops having an overall length approximately equal to a one-half wave length and being separated from one another by lengths of conductor approximately equal to one-quarter of a wave length, and an impedance connecting ono end of said aerial to ground, said impedance being of a value substantially equal to the surge impedance of said aerial for preventing reection of energy over said aerial.
  • An end-wise aerial which is long relative to the working wave length and which consists of a continuous conductor bent to form loops at intervals along the conductor, said loops being at an angle to the direction of radiation which is the general direction of extension of the aerial, the depth of said loops plus the length of the spacing between adjacent loops being substantially equal to one-half the length of a working wave, and high frequency apparatus connected to one end of the aerial and a terminating surge impedance connected to the other end of the aerial.
  • An end-wise uni-directional aerial system which is at least four times the length of the operating wave, comprising a continuous conductor bent to form loops at intervals along conductor, said loops having closely spaced legs and being at an angle to the direction of radiation which is the general direction of extension of the aerial, the depth of said loops plus the leng' of the spacing between adjacent loops being sul stantially equal to one-half the length of the operating wave, and high frequency apparatus connected to one end of said conductor.

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  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Aerials With Secondary Devices (AREA)
  • Suspension Of Electric Lines Or Cables (AREA)
US678613A 1932-07-02 1933-07-01 Directional aerial Expired - Lifetime US2053658A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB18779/32A GB403949A (en) 1932-07-02 1932-07-02 Improvements in or relating to directional aerials

Publications (1)

Publication Number Publication Date
US2053658A true US2053658A (en) 1936-09-08

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ID=10118268

Family Applications (1)

Application Number Title Priority Date Filing Date
US678613A Expired - Lifetime US2053658A (en) 1932-07-02 1933-07-01 Directional aerial

Country Status (4)

Country Link
US (1) US2053658A (fr)
DE (1) DE618912C (fr)
FR (1) FR757828A (fr)
GB (1) GB403949A (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2472106A (en) * 1943-09-20 1949-06-07 Sperry Corp Broad band antenna

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2552043C3 (de) * 1975-11-20 1981-12-17 Flachenecker, Gerhard, Prof. Dr.-Ing., 8012 Ottobrunn Antenne mit einem Dipol, dessen Leiter einen treppenförmigen Verlauf haben

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2472106A (en) * 1943-09-20 1949-06-07 Sperry Corp Broad band antenna

Also Published As

Publication number Publication date
DE618912C (de) 1935-09-18
GB403949A (en) 1934-01-02
FR757828A (fr) 1934-01-05

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