US2153768A - Antenna system - Google Patents

Antenna system Download PDF

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Publication number
US2153768A
US2153768A US78751A US7875136A US2153768A US 2153768 A US2153768 A US 2153768A US 78751 A US78751 A US 78751A US 7875136 A US7875136 A US 7875136A US 2153768 A US2153768 A US 2153768A
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US
United States
Prior art keywords
antenna
length
conductor
impedance
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
US78751A
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English (en)
Inventor
John F Morrison
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.)
AT&T Corp
Original Assignee
Bell Telephone Laboratories Inc
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 Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US78751A priority Critical patent/US2153768A/en
Priority to GB9303/37A priority patent/GB474573A/en
Priority to BE421170D priority patent/BE421170A/xx
Priority to NL82207A priority patent/NL51370C/xx
Priority to DEW3478D priority patent/DE907428C/de
Priority to FR821125D priority patent/FR821125A/fr
Priority to CH214297D priority patent/CH214297A/de
Application granted granted Critical
Publication of US2153768A publication Critical patent/US2153768A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • 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
    • H01Q9/30—Resonant antennas with feed to end of elongated active element, e.g. unipole
    • H01Q9/32—Vertical arrangement of element
    • H01Q9/34—Mast, tower, or like self-supporting or stay-supported antennas

Definitions

  • This invention relates to antennas and particularly to broadcast antennas.
  • quarter wave or half wavelength tower or vertical mast type antennas are rapidly replacing wire type antennas, such as the T antenna, in the broadcast eld.
  • the half wave-length tower antennas now in use are series-excited and base insulated.
  • the quarter wave-length antennas in use are base insulated, although the use of a grounded shunt-excited quarter wave-length antenna has been suggested. It now appears that the voltage distribution in vertical radiators is complex rather than sinusoidal and that vertical antennas, regardless of length, may be satisfactorily connected directly to the earth and the costly equipment ordinarily associated With broadcast antennas, such as base insulators and lightning discharge devices, eliminated.
  • a tower or vertical mast antenna having a wavelength of approximately .58 wave-length is connected to the earth or to a ground radial screen through a path of zero impedance.
  • the transmitter is connected to an intermediate lpoint on the tower by means of a line comprising a coaxial buried non-radiating section adjacent the transmitter and a radiating section adjacent the tower.
  • TheA radiating line section ⁇ is rigidly or adjustably associated with the tower, the connection or tapping point being critically chosen a so that the resistance component of the impedance terminating the coaxial line section equals the surge impedance of said coaxial section.
  • a reactance of the distributed or lumped type is included in the radiating line to compensate or balance the reactance of the coaxial line terminating impedance.
  • the radiating line section is inclined or angularly related to the tower, Whereby the radiation therefrom neutralizes the undesired radiation from the lower antenna portion.
  • FIG. 1 illustrates one embodiment of the invention
  • Figs. 2A, 2B, 2C and 2D are diagrams useful in explaining the operation of the system of Fig. 1;
  • Fig. 3A represents schematically the impedance terminating the coaxial line included in the system of Fig. 1;
  • Fig. 3B illustrates curves representing the various transmission line terminating impedances obtainable in the system of Fig. 1;
  • Fig. 4 represents a slightly different embodiment of the invention.
  • reference numeral I designates a fabricated tower vertical mast antenna mounted directly on a concrete ground base 2 and conductively connected through a path of zero impedance comprising straps 3 to a ground screen 4.
  • the antenna I may have any practical height H, but is preferably .58 wave-length high, and it may, if desired, be of the solid mast type.
  • the antenna I may, if desired, be supported by means of guy wires 5 and associated insulators S.
  • Reference numeral 'l designates a radio frequency transmitter
  • numeral 8 designates a low impedance coaxial transmission line having an inner conductor 9 and an outer conductor I0 which is preferably buried throughout substantially its entire length.
  • the ratio of the outside diameter of the inner conductor to the inside diameter of the outer conductor is preferably in the neighborhood of 3.7.
  • the inner conductor 9 which may be tubular or solid, is connected through an adjustable capacity II to an inclined radiating line conductor I2, the inclined conductor I2 being adjustably or rigidly associated with an intermediate or tapping point I3 of the antenna I.
  • FIGs. 2A, 2B, 2C and 2D designate free space antennas well known in the art and having respectively a quarter and a half wave-length.
  • reference numerals I4 and I5 designate free space antennas well known in the art and having respectively a quarter and a half wave-length.
  • the curves reveal that in the case of an energized half wave-length radiator, the ⁇ voltage at each terminal or end is a maximum and in the case of an energized quarter wave-length radiator, the voltage has .a maximum value at one terminal and a zero value at the other terminal which may be considered the lower terminal.
  • the grounded antenna I of the system of Fig. 1 is energized by transmitter "I and has an aperiodic length or a length equal to approximately a half wave-length, the current distribution and, therefore, the voltage distribution which is in quadrature with the current not being sinusoidal but complex.
  • Curve I6 is based upon actual measurement and shows that the antenna current adjacent the lower terminal of the approximately half wave-length radiator is a maximum and substantially a minimum at the tapping point Iii.
  • the standing wave current in a sense passes through a minimum value and reverses at point i3, wherefore the current rep-resented by the portion of curve I6 below the tapping point I3 is substantially out of phase with the current represented by the portion of curve i8 above the tapping point I3.
  • the coupling current in the lower antenna portion radiates energy and assists the radiation as produced by the antenna current therein, whereby an intense field is established by the lower an- This lower antenna eld unless reduced would, applicant believes, unfavorably affect the total radiation, elevate the direction of maximum antenna action and diminish the desired ground wave propagation while increasing the undesired sky wave propagation.
  • the conductor I' is deliberately inclined so that its radiation neutralizes in part, if not completely, the radiation from the lower portion of the antenna I caused by the coupling current whereby the resultant radiation for the complete system comprising antenna I and conductor I2 corresponds to the current distribution illustrated by curve Il.
  • Curve I8 illustrates, by way of comparison, the current distribution of a .58 wave-length or approximately half wavelength series-excited or base insulated antenna of the prior art; and it will be observed that the radiation effects produced by the grounded antenna of this invention and the costly antenna of the prior art are substantially the same.
  • Arrow i9 represents the direction of flow at a given instant of the current in con.- ductor I2 and corresponds to the direction of the field initially radiated thereby.
  • the eld has a horizontally polarized component 2@ and a vertically polarized component 2l.
  • the current supplied over conductor l2 to the tower divides .at the tapping point i3 and flows in opposite directions therefrom.
  • the resulting vertically polarized field radiated by the upper antenna portion is represented by arrow 22 and the oppositely directed vertically polarized eld established by the lower antenna portion is represented by arrow 23, eld 23 being stronger than eld 22.
  • eld 2i opposes eld 23 and substantially eliminates the effect produced by the coupling current.
  • the vector diagram of Fig. 2D is applicable to vertical antennas excited at an intermediate point and having any length including a quarter wave-length or a half wave-length since the coupling current field and eld of inclined conductor I2 oppose. It is believed to be apparent, therefore, that improved radiation may be obtained not only in the case of shunt-excited aperiodic antennas but also in the case of shuntexcited grounded quarter wave-length antennas by supplying the energy thereto over a radiating conductor angularly related to said antenna.
  • the load impedance ZS terminating the line 8 comprises the surge irnpedance Z0 between the line conductor I2 and the ground, the distributed impedance Za of the upper portion of the antenna and an impedance connected in shunt thereto comprising the impedance Ze of the lower antenna portion, which impedance is serially connected to the ground impedance Zg.
  • Fig. 3B by properly fixing or adjusting the dimensions h and/or d, indicated in Fig.
  • a resistance of 60 ohms and a reactance of 200 ohms may be obtained by making dimension h equal to approximately .03 wave-length, and dimension d equal to approximately .O22 wave-length, or by adjusting h to equal .037 wave-length approximately, and d .012 wavelength.
  • conductor I2 was inclined at an angle of between 40 to 50 degrees, h .and d were each made equal to approximately feet, the antenna being approximately 500 feet high, in order to eliminate the effect of the coupling current and to satisfactorily terminate line 8.
  • the terminating impedance Z1' of the inclined conductor is given by the following equation:
  • an antenna connected to a conducting surface through a path of zero impedance for energy of the operating frequency and having a length other than a quarter wavelength or an odd multiple thereof, and energizing means connected to an intermediatepoint of said antenna.
  • a Vertical tower type antenna having a height in the order of .4 to .6 wave-lengths and its lower terminal connected to the earth through a path of zero impedance, a source of radio frequency energy, and means connecting said source to an intermediate point in said antenna.
  • a half wave-length vertical radiating antenna having its lower terminal connected to a ground screen through a path of' zero impedance, substantially, and means for energizing said antenna at an intermediate point thereof.
  • a vertical antenna having its lower terminal connected directly to the earth for currents of the operating frequency and a height other than a quarter wave-length or a multiple thereof, and means for causing current to flow in said antenna comprising a source of energy and a line comprising a conductor connecting said source and an intermediate point of said antenna whereby a strong field is established by said antenna.
  • a vertical antenna having its lower terminal directly connected to ground, a source of radio frequency energy, a line comprising a conductor connecting said source to an intermediate point of said antenna, and a rea'ctance included in said conductor and having a value and characteristic equal and opposite, respectively, to the primary reactance of the antenna portion below said connecting point.
  • a vertical antenna having a length inthe order of .4i to .6 wave-lengths, said antenna having its lower terminal directly grounded, a source of radio energy frequency and a conductor connecting said source to an intermediate Vpoint of said antenna and having an inclined radiating portion adjacent said antenna.
  • a radio system a vertical tower antenna, a source of energy, a line connecting said source and antenna, said line comprising a non-radiating coaxial section adjacent the source and a radiating section adjacent the antenna, said radiating section being inclined, whereby the field radiated by said section includes a vertically polarized component oppositely directed or phased with respect to the vertically polarized component radiated by the antenna portion below said connecting point and a maximum field is radiated horizontally.
  • a vertical transmitting antenna having a height other than a quarter wavelength and its lower terminal directly grounded, a source of radio frequency energy having one terminal directly grounded, and a coaxial transmission line having its cuter conductor grounded and its inner conductor connected between the remaining terminal of the source and a point on said antenna at which the impedance terminating said line equals approximately the surge impedance of the line.
  • a vertical grounded antenna a source of radio frequency energy, a buried coaxial line, connected to the terminals of said source, an inclined linear conductor connected to an intermediate point of said antenna, a capacitive reactance connected between said inclined conductor and the inner conductor of said line, the length and inclination of said conductor being critically chosen and such as to prevent reiiection on said line.
  • said capacitive reactance comprising a plurality of spaced linear conductors.

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  • Variable-Direction Aerials And Aerial Arrays (AREA)
  • Details Of Aerials (AREA)
  • Support Of Aerials (AREA)
US78751A 1936-05-09 1936-05-09 Antenna system Expired - Lifetime US2153768A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US78751A US2153768A (en) 1936-05-09 1936-05-09 Antenna system
GB9303/37A GB474573A (en) 1936-05-09 1937-04-01 Antenna systems
BE421170D BE421170A (xx) 1936-05-09 1937-04-21
NL82207A NL51370C (xx) 1936-05-09 1937-04-22
DEW3478D DE907428C (de) 1936-05-09 1937-04-23 Vertikalantenne
FR821125D FR821125A (fr) 1936-05-09 1937-04-26 Systèmes d'aériens
CH214297D CH214297A (de) 1936-05-09 1937-04-28 Antennenanlage mit einem vertikalen, selbststrahlenden Antennenmast.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US78751A US2153768A (en) 1936-05-09 1936-05-09 Antenna system

Publications (1)

Publication Number Publication Date
US2153768A true US2153768A (en) 1939-04-11

Family

ID=22146006

Family Applications (1)

Application Number Title Priority Date Filing Date
US78751A Expired - Lifetime US2153768A (en) 1936-05-09 1936-05-09 Antenna system

Country Status (7)

Country Link
US (1) US2153768A (xx)
BE (1) BE421170A (xx)
CH (1) CH214297A (xx)
DE (1) DE907428C (xx)
FR (1) FR821125A (xx)
GB (1) GB474573A (xx)
NL (1) NL51370C (xx)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2467961A (en) * 1946-02-20 1949-04-19 Electronies Res Inc Antenna
US2467962A (en) * 1947-01-28 1949-04-19 Electronies Res Inc High-frequency antenna
US2599705A (en) * 1948-06-16 1952-06-10 Gen Motors Corp Short wave antenna
US2611871A (en) * 1947-08-28 1952-09-23 Alford Andrew Antenna detuning system
US2702345A (en) * 1949-08-25 1955-02-15 Walter Ludwig Radiation and interception of electromagnetic waves
US4001832A (en) * 1974-10-04 1977-01-04 Thomson-Csf Vertical antenna having an off-center supply
US4184165A (en) * 1978-09-07 1980-01-15 Stuart Electronics Tuning system for tower antennas
US20210317822A1 (en) * 2011-07-13 2021-10-14 Ultimate Strength Cable, LLC Guyed Radio Mast

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB190225658A (en) * 1902-11-21 1903-10-08 Marconi Wireless Telegraph Co Improvements in Apparatus used for Wireless Telegraphy.
GB237584A (en) * 1924-07-25 1925-09-24 Telefunken Gmbh Improvements in aerials for wireless telegraphy and telephony
GB338982A (en) * 1929-08-31 1930-12-01 Harold Lister Kirke Improvements relating to masts for wireless aerials

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2467961A (en) * 1946-02-20 1949-04-19 Electronies Res Inc Antenna
US2467962A (en) * 1947-01-28 1949-04-19 Electronies Res Inc High-frequency antenna
US2611871A (en) * 1947-08-28 1952-09-23 Alford Andrew Antenna detuning system
US2599705A (en) * 1948-06-16 1952-06-10 Gen Motors Corp Short wave antenna
US2702345A (en) * 1949-08-25 1955-02-15 Walter Ludwig Radiation and interception of electromagnetic waves
US4001832A (en) * 1974-10-04 1977-01-04 Thomson-Csf Vertical antenna having an off-center supply
US4184165A (en) * 1978-09-07 1980-01-15 Stuart Electronics Tuning system for tower antennas
US20210317822A1 (en) * 2011-07-13 2021-10-14 Ultimate Strength Cable, LLC Guyed Radio Mast

Also Published As

Publication number Publication date
NL51370C (xx) 1941-11-15
BE421170A (xx) 1937-05-31
FR821125A (fr) 1937-11-27
DE907428C (de) 1954-03-25
GB474573A (en) 1937-11-03
CH214297A (de) 1941-04-15

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