US2715184A - Aerials - Google Patents

Aerials Download PDF

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Publication number
US2715184A
US2715184A US775783A US77578347A US2715184A US 2715184 A US2715184 A US 2715184A US 775783 A US775783 A US 775783A US 77578347 A US77578347 A US 77578347A US 2715184 A US2715184 A US 2715184A
Authority
US
United States
Prior art keywords
aerial
conductor
capacities
conductors
band
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
US775783A
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English (en)
Inventor
Cork Edward Cecil
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.)
EMI Ltd
Electrical and Musical Industries Ltd
Original Assignee
EMI Ltd
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 EMI Ltd filed Critical EMI Ltd
Application granted granted Critical
Publication of US2715184A publication Critical patent/US2715184A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/06—Arrays of individually energised antenna units similarly polarised and spaced apart
    • H01Q21/08—Arrays of individually energised antenna units similarly polarised and spaced apart the units being spaced along or adjacent to a rectilinear path
    • H01Q21/10—Collinear arrangements of substantially straight elongated conductive units

Definitions

  • the present invention relates to resonant aerials for radiating or receiving electromagnetic waves over a wide range of frequencies.
  • an aerial which is capable of radiating or receiving electromagnetic waves whose frequency spectrum extends over a wide range.
  • aerials such as dipole aerials
  • tubular conductors rather than single solid wires.
  • an aerial coupled with energizing or receiving apparatus arranged to operate in a wide range of frequencies, said aerial comprising a thin conductor, a plurality of series impedances disposed at intervals along the length of said conductor, said intervals being smaller than one-quarter of the operating wavelength, and said conductor having such a length and the impedances having such magnitude that the aerial is caused to function with substantially uniform efficiency over said range of frequencies like a vibrator having a length equal to a number of quarter wavelengths, said number including one.
  • said aerial may comprise a pair of conductors for operating as a half wavelength resonator, said conductors being inclined to one another to impart a more sharply defined directive diagram.
  • An aerial in accordance with the invention is longer than a simple dipole and hence the aerial has a more extended current distribution than that of a simple dipole.
  • Such an aerial tends to be less selective than a simple dipole since on the one hand the greater extension of current referred to above tends to yield a greater radiating efficiency so that the aerial is more damped. On the other hand, it also tends to be less selective because the aerial tends to be less reactive due to the neutralizing effect on the inductance of the aerial of the capacitative loading.
  • the aerial also has a greater directivity than a simple dipole on account of the more extended current distribution.
  • the capacity loading may be so chosen that the current flow in the region of the extremities of the aerial is augmented.
  • Figure 1 shows a capacity loaded dipole in accordance with one embodiment of the invention
  • Figure 2 shows another capacity loaded aerial in accordance with another embodiment of the invention in which the capacity loading is graded along the arms of the aerial to obtain an augmentation of current at the extremities of the aerial.
  • the aerial shown comprises a pair of radiating or receiving conductors 10 and 11 which lie, for example, in a vertical vplane, and which may be each two free-space wavelengths in length and may be each inclined in said plane at 30 degrees with the vertical.
  • Numerals 12 indicate series capacities inserted in the conductors 10 and 11. Said capacities may or may not be all equal in magnitude and uniformly distributed. It will be observed that the conductors 10 and 11 are nonterminated, that is they are not terminated by their characteristic impedances.
  • each conductor 10 and 11 may extend for a length of two free-space wavelengths, and said capacities may be disposed at uniform intervals of A of a freespace wavelength and graded in magnitude in a uniform manner from 5 micro-micro-farads at the innermost ends of said conductors to 8 micro-micro-farads at the extremities thereof.
  • the diameter of the conductors may be approximately 4 inch.
  • Such conductors will have an impedance when unloaded of approximately 400 ohms and thus the impedances of the capacities aforesaid are small compared with the impedance of the unloaded conductors.
  • the aerial operates substantially as a half-wavelength resonator in said Wide range of frequencies substantially a quarter wavelength of current distribution existing along each conductor 10 and 11 of the aerial.
  • the directive diagram of the aerial is similar in character to the two lobes of a dipole except that the lobes are more sharply defined. If the conductors 10 and 11 are co-linear the diagram is symmetrical but each lobe may show a tendency to split into two lobes if the conductors and 11 are excessively long. By inclining the conductors 10 and 11 towards one another as shown in Figure 1, the tendency for the lobes to split is overcome but the directive diagram is rendered slightly asymmetrical.
  • the aerial is formed of a plurality of tubular conductors 15. These elements are insulated from one another and as indicated in Figure 2 are capacitatively coupled together by overlapping their ends.
  • a non-uniform capacitative series loading of the aerial can be achieved giving a half-wavelength current distribution along the aerial in which more current flows in the region of the extremities of the aerial than if the aerial were in the normal form of an unloaded straight rod, wire or tube, that is to say, in the form of a simple dipole.
  • an aerial according to the invention may consist of a straight wire loaded by series connected capacities distributed non-uniformly in magnitude or spacing or both so as to give augmentation at the extremities of the aerial.
  • the aerial shown in Figure 1 of the drawings can, as stated, be connected to feeding or receiving apparatus at the adjacent ends 13 and 14 and likewise the aerial shown in Figure 2 can also be connected at the centrally disposed conductor 15 to feeding or receiving apparatus.
  • the extremities of the aerials may be connected to said feeding or receiving apparatus.
  • An aerial coupled with apparatus for operation in a wide band of frequencies extending over at least 8 per cent of the mean frequency in the range of said band said aerial comprising a thin conductor having one end coupled to said apparatus and its other end left free, a plurality of series capacities having small impedances at the operating wavelength compared with the impedance of said conductor without said capacities, said capacities having magnitudes increasing towards the free end of said conductor and being disposed along the length of said conductor at intervals smaller than one quarter of the operating wavelength, said intervals and the magnitudes of said capacities being proportioned to tune said aerial for operation in said band with a reflection coefficient of less than 10 per cent.
  • An aerial coupled with apparatus for operation in a wide band of frequencies extending over at least 8 per cent of the mean frequency in the range of said band said aerial including a pair of arms inclined to one another and each comprising a thin conductor, adjacent ends of said conductors being coupled to said apparatus and their outer ends being left free, a plurality of series capacities having small impedances at the operating wavelength compared with the impedance of each con- 4 ductor without said capacities, said capacities having magnitudes increasing towards the free end of each conductor and being disposed along the length of each conductor at intervals smaller than one quarter of the operating wavelength, said intervals and the magnitudes of quency in the range of said band, said aerial comprising a thin conductor having one end free, a plurality of series capacities having magnitudes increasing towards the free end of said conductor disposed along the length of said conductor at intervals limited substantially to a maximum of one-twelfth of the operating wavelength, the magnitudes of said capacities and their spacing being proportioned to cause said aerial to operate with a reflection coefi
  • a tuned aerial for operation over a band of frequencies extending over at least 8 per cent of the-mean frequency in the range of said band said aerial comprising a thin conductor having one end free, a plurality of series capacities having magnitudes increasing towards the free end of said conductor disposed along the length of said conductor at intervals limited substantially to a maximum of one-twelfth of the operating wavelength, the magnitudes of said capacities and their spacing being proportioned to cause said aerial to operate with a reflection coefiicient of less than 10 per cent, said conductor comprising a plurality of sections, and said sections having adjacent overlapping ends and means for insulating said overlapping ends to provide said capacities.

Landscapes

  • Details Of Aerials (AREA)
  • Aerials With Secondary Devices (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
US775783A 1946-10-01 1947-09-24 Aerials Expired - Lifetime US2715184A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB268705X 1946-10-01

Publications (1)

Publication Number Publication Date
US2715184A true US2715184A (en) 1955-08-09

Family

ID=10250507

Family Applications (1)

Application Number Title Priority Date Filing Date
US775783A Expired - Lifetime US2715184A (en) 1946-10-01 1947-09-24 Aerials

Country Status (5)

Country Link
US (1) US2715184A (de)
CH (1) CH268705A (de)
DE (1) DE833064C (de)
FR (1) FR953486A (de)
GB (1) GB628986A (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2887682A (en) * 1954-06-18 1959-05-19 Emi Ltd Aerials
US3159839A (en) * 1955-07-07 1964-12-01 Donald L Hings Driven dipole coupled to a colinear array spaced with respect to the first fresnel zone
US3530474A (en) * 1968-07-02 1970-09-22 Us Army Antenna with adjustable-ratio dual capacitive loading
US4092646A (en) * 1975-12-31 1978-05-30 The Marconi Company Limited Flexible antenna with capacative plate coupling
US4238800A (en) * 1978-02-07 1980-12-09 The Marconi Company Limited Whip antenna with capacitive loading
US4568944A (en) * 1982-07-28 1986-02-04 U.S. Philips Corporation Y-Shaped dipole antenna

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL160940B (nl) * 1950-05-03 Spanstaal Werkwijze en inrichting voor het bepalen van het soortelijk gewicht of de transportconcen- tratie aan baggerspecie van een door een leiding stromende suspensie van baggerspecie en water.
DE975023C (de) * 1952-07-24 1961-07-06 Heinz Dr Phil Graziadei Breitband-Richtstrahlantenne mit einer leitenden Flaeche variabler Breite
US2924823A (en) * 1954-12-08 1960-02-09 Emi Ltd Separate adjacent antennas for different bands with means to reduce cross coupling
US2967300A (en) * 1957-11-22 1961-01-03 L A Young Spring & Wire Corp Multiple band antenna
US3064257A (en) * 1958-02-14 1962-11-13 James D Guest Antenna with adjustable tuning reactance
GB2148604B (en) * 1983-10-18 1988-01-06 Plessey Co Plc Monopole aerial
GB2148605B (en) * 1983-10-18 1988-02-17 Plessey Co Plc Whip aerial
GB2171258B (en) * 1985-02-19 1988-12-07 Plessey Co Plc Aerials

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1790646A (en) * 1925-05-09 1931-02-03 alex anderson
US1839426A (en) * 1924-07-25 1932-01-05 Drahtlose Telegraphie Gmbh Antenna
US1935373A (en) * 1929-03-29 1933-11-14 Rca Corp Antenna
US2208749A (en) * 1937-02-09 1940-07-23 Emi Ltd Aerial system
US2258406A (en) * 1938-04-16 1941-10-07 Rca Corp Wide band antenna
US2272608A (en) * 1939-12-19 1942-02-10 Internat Telephone Dev Co Inc Antenna matching structure
US2276910A (en) * 1939-08-03 1942-03-17 Mackay Radio & Telegraph Co Phase shifting network
US2352977A (en) * 1942-09-18 1944-07-04 Gen Electric Self-compensating video antenna
US2409542A (en) * 1942-11-20 1946-10-15 Rca Corp High-frequency transducer system
FR916270A (fr) * 1944-05-02 1946-12-02 Emi Ltd Antenne aérienne de rayonnement et de réception des ondes électromagnétiques dans une large gamme de fréquence
US2419552A (en) * 1943-06-12 1947-04-29 Standard Telephones Cables Ltd Radio antenna

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1839426A (en) * 1924-07-25 1932-01-05 Drahtlose Telegraphie Gmbh Antenna
US1790646A (en) * 1925-05-09 1931-02-03 alex anderson
US1935373A (en) * 1929-03-29 1933-11-14 Rca Corp Antenna
US2208749A (en) * 1937-02-09 1940-07-23 Emi Ltd Aerial system
US2258406A (en) * 1938-04-16 1941-10-07 Rca Corp Wide band antenna
US2276910A (en) * 1939-08-03 1942-03-17 Mackay Radio & Telegraph Co Phase shifting network
US2272608A (en) * 1939-12-19 1942-02-10 Internat Telephone Dev Co Inc Antenna matching structure
US2352977A (en) * 1942-09-18 1944-07-04 Gen Electric Self-compensating video antenna
US2409542A (en) * 1942-11-20 1946-10-15 Rca Corp High-frequency transducer system
US2419552A (en) * 1943-06-12 1947-04-29 Standard Telephones Cables Ltd Radio antenna
FR916270A (fr) * 1944-05-02 1946-12-02 Emi Ltd Antenne aérienne de rayonnement et de réception des ondes électromagnétiques dans une large gamme de fréquence

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2887682A (en) * 1954-06-18 1959-05-19 Emi Ltd Aerials
US3159839A (en) * 1955-07-07 1964-12-01 Donald L Hings Driven dipole coupled to a colinear array spaced with respect to the first fresnel zone
US3530474A (en) * 1968-07-02 1970-09-22 Us Army Antenna with adjustable-ratio dual capacitive loading
US4092646A (en) * 1975-12-31 1978-05-30 The Marconi Company Limited Flexible antenna with capacative plate coupling
US4238800A (en) * 1978-02-07 1980-12-09 The Marconi Company Limited Whip antenna with capacitive loading
US4568944A (en) * 1982-07-28 1986-02-04 U.S. Philips Corporation Y-Shaped dipole antenna

Also Published As

Publication number Publication date
GB628986A (en) 1949-09-08
CH268705A (de) 1950-05-31
DE833064C (de) 1952-03-03
FR953486A (fr) 1949-12-07

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