US2285669A - Antenna - Google Patents

Antenna Download PDF

Info

Publication number
US2285669A
US2285669A US211860A US21186038A US2285669A US 2285669 A US2285669 A US 2285669A US 211860 A US211860 A US 211860A US 21186038 A US21186038 A US 21186038A US 2285669 A US2285669 A US 2285669A
Authority
US
United States
Prior art keywords
antenna
conductors
impedance
conductor
wave
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
US211860A
Other languages
English (en)
Inventor
Lehmann Gerard
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.)
Ind Radioelectriques SA Des
INDUSTRIES RADIOELECTRIQUES SA
Original Assignee
Ind Radioelectriques SA Des
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ind Radioelectriques SA Des filed Critical Ind Radioelectriques SA Des
Application granted granted Critical
Publication of US2285669A publication Critical patent/US2285669A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/16—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole
    • H01Q9/26—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength

Definitions

  • the present invention relates to antennas or systems of antennas for emitting or receiving radio-electric waves. It is applicable both to receiving antennas and to emitting antennas and it is more especially concerned with antennas utilized in the case of short or very short waves.
  • antennas are generally located at places where access is practically impossible (top of a mast or of a, building) and anyway it is very difiicult to modify their lengths once they have been fitted.
  • the object of the present invention is to provide an antenna system which complies with this condition without requiring any modification of the mechanical and geometrical properties of the aerial when mounted in position.
  • the invention will be set forth by referring more specifically to the case of a bipolar antenna, but of course the invention is not in any way limited to this particular case and it applies'to all kinds of aerials constituted either by combinations of bipolar antennas or, more generally, to systems of conductors in which stationary waves are produced.
  • the elementary study of progressive or travelling waves shows that when The essential feature of the present invention consists in replacing the conductor, or a conductor element, of an aerial system. by two wires located at a short distance from each other and forming a circuit closed through an impedance intended to absorb the progressive waves without reflecting them.
  • the two elementary conductors are directly connected together at their ends and in their middle parts there are inserted, respectively, the current feed system for one of them, and this impedance for the other one.
  • the value of this impedance determined experimentally, is substantially equal to the characteristic impedance of the line equivalent to this pair of conductors.
  • this system of two wire elements may be considered, from the point of view of the current feed, as equivalent to a conductor closed through' its characteristic impedance, so that the feed characteristics remain constant when the wave-length varies.
  • Antennas of the di-pole type, employed with short wave lengths have characteristics (especially the impedance) which are very readily influenced by objects located near them, and especially by metallic bodies. This is above all due to the fact that the lines of force of the fields produced and passing from one portion to the other of the wire constituting the antenna spread out greatly around thelatter and consequently are modified by the adjacent dielectrics or conductors; these are antennas which may for this reason he called open antennas.
  • the antenna of the present invention is in this sense a closed antenna since the lines of force passing from one portion ofthe wire to the other remain in the immediate neighborhood of the antenna, and hence it is insensitive to local objects, an insensitivity that is completely proved by experience.
  • Fig. 1 shows an aerial constituted, in the known manner, by a bipolar conductor
  • Fig. 2 diagrammatically shows an aerial of equivalent construction, made according to the present invention
  • Fig. 3 is a similar view, with indications thereon for the explanation of the operation of this system;
  • Fig. 4 diagrammatically shows another embodiment of the invention.
  • Fig. l ineludes: at I the emitting winding for the feed of current to the aerial, at 2 the feed conductors, at 3 the coupling system, at 4 the two branches of the bi-polar conductor, the length of each branch being equal, in the case illustrated by this figure, to one fourth of the wave length that is emitted.
  • Fig. 2 shows an embodiment of the system according to the invention, reference character I still designating the emitting means and 2 the feeding conductors.
  • the aerial includes two elementary wires, to wit CABD on the one hand, and CEFD on the other hand, these rectilinear wire elements being parallel and located at a small distance from each other as compared to the wave length that is emitted.
  • the elementary wires are connected together at their ends and D by regular loops the size of which (the diameter in the case of a circular loop) is small with respect to the diameter of the wires.
  • an impedance 6 the value of which is substantially equal to the characteristic impedance of the double conductor ACE, BDF.
  • points A and B are connected to the feeding system through wires 2.
  • This arrangement has been shown by way of example as it is the simplest one. But other coupling means, for instance one including a transformer, might be used according to the invention.
  • the radiation produced by the feeding conductors in themselves is zero since, at each point of a transverse section thereof, the currents, at any time, are equal and of opposed directions so that the equivalent current, from the point of view of the radiations, is "zero.
  • the wave-length can vary within a relatively wide range.
  • the ratio in which L is the distance CD should be greater than 0.8 and smaller than 3.
  • the upper limit is determined chiefly by the admissible loss of energy produced by the ohmic resistance of impedance 6, and the lower limit is determined by the drop of the radiating power.
  • the impedance of the aerial remains substantially fixed, which involves that the impedance of the feeder also remains fixed and the radiating power keeps a high value.
  • Fig. 4 illustrates the application of the invention in the case of an aerial having a single branch of conductors and of the quarter-wave type. In this case also:
  • I is the emitting means 2 the feeder conductors
  • the aerial is constituted y the elements AC and CE of parallel rectilinear Wires.
  • the end E closes on the feeder generally by being earthed, through the intermediate of impedance I the value of which is equal to the characteristic impedance.
  • the invention is not limited to these examples and it is applicable to all aerials including bipolar systems (provided that these systems do not include inert reflecting bipolar antenna elements) which may be devised especially with a view to obtaining directive efiects.
  • the present invention therefor permits of replacing tuned bipolar antenna elements by aperiodic systems which can be used within wide ranges of wave-lengths.
  • the present invention permits, in any aerial system including conductors in which stationary waves are formed, of replacing each of these conductors by two wires through which flow progressive waves moving in opposite directions, which permits, while keeping the radiating power of the aerials, of utilizing them within a very wide range of wave-length.
  • An omni-directional aerial element constituted by two similar conductors connected together at one of their ends and arranged parallel to each other and spaced apart to an extent which is very small with respect to the shortest wave to be handled by said element, an impedance substantially equal to the characteristic impedance of said two conductors for terminating the end of one of said conductors remote from the connected end whereby said conductors are traversed by progressive waves, a feeder connected to the other of said two conductors remote from the connected end, said two conductors being so close together that the aerial element is characterized by its substantially constant radiation characteristics over a wide range of wavelengths,
  • a bipolar antenna element comprising: in combination, two wire elements directly connected together at their respective ends, said wire elements being rectilinear, parallel to each other and located close to each other compared to the shortest wavelength employed, one of said elements being adapted to be fed with current in its middle part, and an impedance of a value substantially equal to the characteristic impedanceof the line formed by said two wire elements, said impedance being connected in series with the middle part of the other of said wire elements, said impedance being calculated to let progressive waves moving in opposed directions to flow through said wire elements, said antenna element being characterized by its substantially constant radiation characteristics over a wide range of wave-lengths.
  • an antenna element for said system which comprises, in combination, two elementary wires directly connected together at at least one of their respective ends, said elementary wires being rectilinear, parallel to each other and located close to each other compared to the shortest wavelength employed, means for connecting said current feed means in series with an intermediate part of one of said elementary wires, and an impedance inserted in the other elementary wire of a value equal to the characteristic impedance of the line formed by these two elementary wires, so as to let progressive Waves moving in opposed directions to flow through said elementary wires, said antenna element being characterized by its substantially constant radiation characteristics over a wide range of wave-lengths.
  • An antenna system adapted for use over a wide range of high frequencies, comprising: a plurality of antenna conducting elements; leadin conductors connected to a pair of said antenna elements; a second pair of said antenna elements disposed adjacent and substantially parallel to corresponding elements of said first pair of antenna elements and connected to respective ends of said first pair of antenna elements; the spacing between each of said first pair of elements and the adjacent and parallel one of said second pair of elements being small compared to the shortest wavelength employed whereby these elements per se are substantially non-directive; and an impedance equal substantially to the characteristic impedance of said antenna elements conductors connected between said second pair of antenna elements whereby progressive waves moving in opposite directions flow through adjacent ones of said antenna conducting elements.
  • An antenna system adapted for use over a wide range of high radio frequencies, comprising: a pair of antenna conductors arranged substantially as a di-pole; lead-in conductors for either feeding current to or receiving current from said antenna conductors; a second pair of antenna conductors positioned side by side to and only a small distance, compared to the shortest wavelength employed, away from said first pair of antenna conductors; an impedance bearing a predetermined impedance ratio to the characteristic impedance of said pair of antenna conductors and being connected to adjacent ends of said second pair of antenna conductors; and connections between the opposite ends of said second pair of antenna conductors and the respective ends of said first pair of antenna conductors.
  • An antenna system comprising: a substantially non-directive element having two parallel conductors spaced only a short distance from each other compared to the shortest wavelength employed; said conductors being connected to each other at one end; lead-in conductors; means for connecting one of said lead-in conductors to one of said parallel wires; an impedance of a value substantially equal to the characteristic impedance of the line formed by said two conductors, said impedance being connected to the other one of said parallel wires; and means for connecting said impedance to another one of said lead-in conductors, said impedance being of a magnitude such that progressive waves moving in opposite directions are permitted to flow through said parallel antenna conductors, said parallel conductors being positioned so close to each other that the antenna element may be used over a wide range of wave-lengths with substantially constant radiation characteristics.
  • An omni-directional aerial element as set forth in claim 1 including, a second feeder and a grounding connection between said impedance and said second feeder.
  • An antenna system comprising a conductor having a pair of separated arms, another conductor arranged parallel to said first conductor and closely spaced therefrom, a transmission line directly connected-to the adjacent ends of said pair of arms, and means for connecting said arms to said other conductor at points removed from said adjacent ends, said other conductor having a lumped resistor located substantially in the center thereof connected electrically in series relation thereto to provide a traveling wave effect for Waves traveling along said conductors,
  • An antenna system comprising a conductor having a pair of separated arms, another conductor arranged parallel to said first conductor and closely spaced therefrom,-a transmission line directly connected to the adjacent ends of said pair of arms, and means for connecting said arms to said other conductor at points removed from said adjacent ends, said other conductor having a lumped impedance located substantially in the center thereof connected electrically in series relation thereto to provide a traveling wave effect for waves traveling along said conductors 11.
  • An antenna system operative over a wide range of frequencies comprising an aerial conductor having a pair of separated arms arranged end to end and providing terminals at the adjacent ends of said arms, another aerial conductor arranged parallel to said first conductor and spaced very close thereto relative to the length of the operating wave, connections between the ends of said last conductor and points on said arms removed from the adjacent ends of said arms,
  • the impedance of said antenna system at said terminals is increased over that of a single conductor dipole, and a two-wire open feeder line having a predetermined impedance directly connected to said terminals, an impedance connected into said other aerial conductor, said last impedance being of the order of the characteristic impedance of said aerial conductors whereby said antenna system has an extremely flat i-rnpedance versus frequency characteristic over said range of frequencies.
  • An antenna system comprising a conductor having a pair of separated arms, another conductor arranged parallel to said first conductor and closely spaced therefrom, a transmission line directly connected to the adjacent ends 'of said pair of arms, and means for connecting said arms to said other conductor at points removed from said adjacent ends, said other conductor having an impedance located substantially in the center thereof connected electrically in series relation thereto of such value as to produce a traveling wave effect for waves traveling along said conductors.

Landscapes

  • Variable-Direction Aerials And Aerial Arrays (AREA)
US211860A 1938-06-08 1938-06-04 Antenna Expired - Lifetime US2285669A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR50002T 1938-06-08

Publications (1)

Publication Number Publication Date
US2285669A true US2285669A (en) 1942-06-09

Family

ID=8685066

Family Applications (1)

Application Number Title Priority Date Filing Date
US211860A Expired - Lifetime US2285669A (en) 1938-06-08 1938-06-04 Antenna

Country Status (3)

Country Link
US (1) US2285669A (fr)
FR (2) FR833239A (fr)
GB (1) GB500162A (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2566491A (en) * 1946-03-15 1951-09-04 Belmont Radio Corp Antenna construction
US2971192A (en) * 1957-11-12 1961-02-07 Itt Wideband folded monopole antenna
US2994876A (en) * 1957-01-14 1961-08-01 Bengt Adolf Samuel Josephson Ultrashortwave antenna
US3295137A (en) * 1964-09-08 1966-12-27 Collins Radio Co Shortened folded monopole with radiation efficiency increased by ferrite loading
US3806795A (en) * 1972-01-03 1974-04-23 Geophysical Survey Sys Inc Geophysical surveying system employing electromagnetic impulses
US4028707A (en) * 1974-01-30 1977-06-07 The Ohio State University Antenna for underground pipe detector
US5892484A (en) * 1996-10-30 1999-04-06 Amplifier Research Corporation E-field generator

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1291803B (de) * 1965-01-04 1969-04-03 Blankenburg Antennen Logarithmisch-periodische Dipolantenne
US4423423A (en) * 1980-09-09 1983-12-27 L. Barker & Williamson, Inc. Broad bandwidth folded dipole antenna
US5189432A (en) * 1991-08-15 1993-02-23 Harris Corporation Radiating antenna cable apparatus
ITFI980103A1 (it) * 1998-05-04 1998-08-04 Giovannini Elettromeccanica Di Antenna ricevente e trasmittente super compatta con copertura continua da 1, 5 a 200 mhz, senza ausilio di accordatori di qualsiasi genere o natura, senza l'ausilio di sistemi di telecomando di qualsiasi genere o natura per cambiare frequenza nello s

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2566491A (en) * 1946-03-15 1951-09-04 Belmont Radio Corp Antenna construction
US2994876A (en) * 1957-01-14 1961-08-01 Bengt Adolf Samuel Josephson Ultrashortwave antenna
US2971192A (en) * 1957-11-12 1961-02-07 Itt Wideband folded monopole antenna
US3295137A (en) * 1964-09-08 1966-12-27 Collins Radio Co Shortened folded monopole with radiation efficiency increased by ferrite loading
US3806795A (en) * 1972-01-03 1974-04-23 Geophysical Survey Sys Inc Geophysical surveying system employing electromagnetic impulses
US4028707A (en) * 1974-01-30 1977-06-07 The Ohio State University Antenna for underground pipe detector
US5892484A (en) * 1996-10-30 1999-04-06 Amplifier Research Corporation E-field generator

Also Published As

Publication number Publication date
FR50002E (fr) 1939-11-10
GB500162A (en) 1939-02-03
FR833239A (fr) 1938-10-17

Similar Documents

Publication Publication Date Title
US2283897A (en) Antenna system
US2267889A (en) Antenna with wide wave range
US3945013A (en) Double omni-directional antenna
US2455403A (en) Antenna
US3348228A (en) Circular dipole antenna array
US2285669A (en) Antenna
US2380333A (en) High frequency antenna
US2611869A (en) Aerial system
US2495399A (en) Antenna system
US2998604A (en) Guy wire loaded folded antenna
US2153589A (en) Antenna
US3534372A (en) Horizontal broad-band omnidirectional antenna
US3550145A (en) Manipole broadband antenna
GB1291275A (en) Log-periodic antenna array having closely spaced linear elements
US4131895A (en) Apparatus for isolating from ground and exciting a conductive tower for use as a vertical antenna
US3101474A (en) Log periodic type antenna mounted on ground plane and fed by tapered feed
US2153975A (en) Radio direction finder
US2267613A (en) Broadcast antenna
US3103011A (en) Inductively loaded folded antenna
US2732551A (en) Spherical cage antenna
US2860339A (en) Ultra-high frequency antenna unit
US2153298A (en) Aerial
US2998605A (en) Antenna system
US11417962B2 (en) Tower based antenna including multiple sets of elongate antenna elements and related methods
US3363254A (en) Broadband antenna with direction of radiation determined by frequency