US2744249A - Antenna feed systems - Google Patents

Antenna feed systems Download PDF

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Publication number
US2744249A
US2744249A US334142A US33414253A US2744249A US 2744249 A US2744249 A US 2744249A US 334142 A US334142 A US 334142A US 33414253 A US33414253 A US 33414253A US 2744249 A US2744249 A US 2744249A
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US
United States
Prior art keywords
antenna
aperture
feed point
elements
transmission line
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
US334142A
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English (en)
Inventor
Edward H Shively
William S Brandberg
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
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RCA Corp
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
Priority to FR1094683D priority Critical patent/FR1094683A/fr
Priority to BE526052D priority patent/BE526052A/xx
Priority to NLAANVRAGE7811702,A priority patent/NL184706B/xx
Priority to NL91730D priority patent/NL91730C/xx
Priority to US334142A priority patent/US2744249A/en
Application filed by RCA Corp filed Critical RCA Corp
Priority to GB1036/54A priority patent/GB739618A/en
Priority to CH330332D priority patent/CH330332A/de
Priority to DER13474A priority patent/DE1009678B/de
Application granted granted Critical
Publication of US2744249A publication Critical patent/US2744249A/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
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/0006—Particular feeding systems
    • H01Q21/0037—Particular feeding systems linear waveguide fed arrays
    • H01Q21/0043—Slotted waveguides
    • H01Q21/0062—Slotted waveguides the slots being disposed around the feeding waveguide
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
    • H01Q13/10—Resonant slot antennas
    • H01Q13/12—Longitudinally slotted cylinder antennas; Equivalent structures
    • 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
    • H01Q21/20—Arrays of individually energised antenna units similarly polarised and spaced apart the units being spaced along or adjacent to a curvilinear path
    • H01Q21/205—Arrays of individually energised antenna units similarly polarised and spaced apart the units being spaced along or adjacent to a curvilinear path providing an omnidirectional coverage
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
    • H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
    • H01Q3/30—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array
    • H01Q3/32—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array by mechanical means

Definitions

  • This invention relates to antennas, and particularly pertains to feeding systems for antenna arrays having an aperture several wavelengths long at the operating frequency.
  • An antenna having a vertical radiation pattern which varies as the consecant of the angle of depression may be satisfied by the use of an antenna having a vertical radiation pattern which varies as the consecant of the angle of depression. Although this relation is not strictly true because of ground reflection and intervening obstacles, it provides a useful approximation in practice.
  • An antenna aperture which is uniformly illuminated along its length by the radio frequency energy has a pattern characteristic which is generally similar to this consecant distribution, except that deep nulls occur wherein the signal strength is theoretically zero.
  • aperture in this specication and the appended claims is used to denote the area in space over which the antenna interchanges radio frequency energy between itself and surrounding space.
  • length of aperture denotes one dimension of the area of aperture, customarily considered the longest dimension of the area of aperture over which the antenna radiates energy into surrounding space or extracts a passing radio wave therefrom.
  • the absolute value of signal strength necessary to produce a useable signal at the home receiver is the same at all points in the primary service area.
  • the signal strength available at receivers at varying distances from the transmitting antenna decreases in proportion to the distance from the antenna.
  • a vertical radiation pattern characteristic may be calculated for any given antenna height to take account of this variation in field strength for different distances and produce equal signal strength at all locations in the primary service area.
  • the cosecant eld strength distribution mentioned above provides the desired uniform signal strength in the service area.
  • This invention has as an object the elimination of nulls in the vertical pattern of ultrahigh frequency broadcast antenna systems.
  • Another object of this invention is to provide an antenna array which has a vertical pattern characteristic wherein the signal strength does not fall to deep nulls and also wherein the vertical pattern can be tilted electrically by a simple mechanical adjustment.
  • a further object of this invention is to provide an antenna feed system for ultrahigh frequency broadcasting antenna arrays which produces a shaped vertical pattern characteristic to yield more uniform coverage of the primary service area and in which the beam tilting of the vertical pattern can be changed electrically by a simple mechanical adjustment.
  • an improved antenna feed system for antenna arrays which include a plurality of radiating elements arranged over an aperture a plurality of wavelengths long.
  • the antenna elements are divided into a number of groups of elements occupying different lengths of aperture, and each group is fed with the same amount of power.
  • An asymmetrical power distribution along the aperture of the array results from this feed system which produces a vertical radiation pattern (for a vertical array and horizontal polarization) having no nulls at all wherein the iield strength drops to zero either theoretically or actually.
  • An embodiment of the invention is described in connection with a slotted cylinder antenna having from 14 to 13 layers of slots and suitable for ultrahigh frequency television broadcasting. lt should be understood, however, that the principles of the invention are applicable as well to other antenna arrays.
  • two groups of antenna elements are fed from a single feed point, but are adjusted to present the same impedance, and therefore receive equal proportions of the total power.
  • a representation of the power distribution per antenna element along the length of the antenna array is therefore asymmetrical.
  • Figure l is a graphical representation of power distribution across an antenna array aperture used in explaining the invention.
  • Figure 2 is a graphical showing of lield strength patterns used in explaining the invention.
  • Figures 3 ⁇ and 4 are lield pattern curves of center-fed arrays
  • Figure 5 is a field pattern curve of an antenna array fed in accordance with the invention.
  • FIG. 6 is an elevation, partly in section, of a slotted cylinder antenna embodying the invention.
  • Figure l represents the power distribution along an antenna aperture having a length of 2a with the center of total power removed from the electrical center of the antenna by the quantity A and Figure 2 is a graphical showing of the relative eld strength of an antenna fed according to the power division of Figure l represented as two separate antennas electrically removed by the'distance D. l
  • Figure 2 illustrates representative radiation patterns or" two groups of elements containing different numbers of elements and occupying different linear dimensions of aperture.
  • the upper section has a narrower main beam, while the lower section, due to its shorter aperture, has a somewhat broader main beam.
  • lf equal total power is fed to each of the groups, the areas included iu the graphical representation of both of the radiation patterns of the 4two groups will be the same.
  • nulls in the individual patterns do not occur at the same depression angle, and thus do not occur at all in the overall radiation pattern characteristic (which is the vector summation of the two separately represented pattern characteristics shown in Figure 2). Furthermore, nulls in the over-all pattern which would normally be due to cancellation of radiation from the two sections in known antennas do not occur in the antenna of the invention because the amplitudes of the radio frequency field radiated by each section of the antenna are unequal at those depression angles where they are in phase opposition.
  • the amount that the feed point may be removed from the physical and electrical center of the antenna aperture and still obtain the beneficial result of this invention may vary from 5% to 25% of the total length of the apen ture 2a. This represents offsetting the feed point about l1/2 wavelengths in a 30 wavelength aperture up to olfsetting the feed point 4*/2 wavelengths in an i3 wavelength aperture.
  • An offset of less than 5% 4ces not create sutiicient power asymmetry in a long aperture antenna to ll in the nulls properly, while displacing the feed point more than 25% from the center of the aperture may create bandwidth problems as well as pattern scanning with frequency.
  • Figure 3 shows the calculated and measured field patterns of a slotted cylinder -antenna having 18 layers of slots spaced 1.5 wavelengths at the operating frequency, three longitudinal slots per layer equally spaced around the cylinder, each slot having a length of approximately 1.3 wavelengths at the operating frequency, with the slots in adjacent layers staggered 60 to give an om nidirectional horizontal pattern.
  • the antenna was fed at its electrical center with equal power input to the two halves of the antenna array.
  • the solid line 21 indicates an actual measured field strength pattern of the antenna array, while the dot-dash line 23 indicates the theoretical eld pattern of the array described.
  • the part of the graph to the left of the zero mark on the abscissa and showing positive (l) values of elevation represents power directed above vthe horizon and hence wasted power for most applications.
  • the part of the graph to the right of the zero mark on the abscissa and showing negative values of elevation represents power directed below the horizon and hence useful power in the primary service area of the broadcasting station.
  • the largest negative values of angle on the abscissa denote points closer to the antenna location, while the lower negative values of angle denote points closer to the horizon.
  • the theoretical or calculated vertical pattern falls to deep nulls wherein the radiated field strength is zero at a number of points along the abscissa of the curve. These nulls occur where the differences in the radiated iield from the upper and lower halves of the antenna are in phase opposition at various elevation or depression angles, or where the nulls in the individual patterns of the upper and lower halves occur at ⁇ the same depression angle.
  • Figure 4 shows a typical measured pattern 2.4 of an antenna like that described to obtain the pattern of Figure 3 in which the antenna was fed near thc electrical center, but with the feed point removed a small amount (less than 2 percent of the total length of the aperture) to eiiiect a difference in phase in the radio frequency energy fed to the upper and lower halves.
  • This dilfcrenc in phase produces the electrical beam tilt of the antenna and in the case illustrated by the pattern shown in Figure 4, the main beam was tilted downward (192.
  • the beam tilting produced by the ditlerence in phase between the two halves of the antenna has a concomitant effect of providing a certain small amount of null till-in.
  • lt may be observed that there are still points of low signal strength occurring at angles of depression of about Ll-l/z", 9, and l3l/z" for the particular antenna array measured.
  • the eld intensity probably would not fall to such low levels for every available receiving antenna location at each home installation.
  • Scattering ef- ⁇ fects, ground reliections, and possible propagation by other than the direct path combine to produce useable signals in what would be expected to be a low signal strength area.
  • the feeding system of the present invention may be utilized to lessen the likelihood of the lield intensity in the primary service area falling below a desired value, to achieve better null fill-in, and to provide a vertical radiation pattern characteristic more closely approaching a cosecant function of angular depression from the horizon.
  • Figure 5 is a measured lield pattern of a slotted cylinder antenna like those utilized to obtain the patterns of Figures 3 and 4 but fed in accordance with this invention.
  • the 18 layers of slots were divided into two groups, ten slots in the upper layer and eight slots in the lower layer, with equal power being fed to the two groups. T his resulted in each layer of slots in the lower group being fed with more radio frequency energy than each layer in the upper group.
  • a one degree beam tilt was obtained by displacing the feed point from its normal position midway between Athe eighth and ninth layers of slots to produce the necessary difference in phase of the two currents.
  • the solid line 2S indicates the measured field pattern of the antenna described
  • the dot-dash curve 27 is a representative cosecant field strength distribution indicated above as being highly desirable for uniform coverage of the service area.
  • Points on the actual measured eld strength curve 25 in Figure 5 which are above the dot-dash curve 27 represent more signal strength at the receiver location than is necessary for good reception, and in one sense, therefore, represent wasted power.
  • FIG. 6 is a view, partly in section, of a slotted cylinder antenna embodying the invention like that described to obtain the field pattern characteristic shown in Figure 5
  • the slotted cylinder antenna has an outer conductive cylinder 31 with a plurality of slots 33 arranged in layers around the periphery thereof. There are three slots 33 in each layer, equally spaced around the conductive tubular member 31. Each layer of slots 33 is staggered 60 with respect to a next adjacent layer. There are 18 layers of slots in all, each slot having a length of 1.3 wavelengths and being spaced center to center 11/2 wavelengths at the operating frequency.
  • Radio frequency energy is distributed to the 18 layers of slots by a coaxial feed system in which the outer conductive tubular member 31 serves as the outer conductor of a coaxial transmission line, and an intermediate tubular member 35 within and coaxial with the tubular member 31 serves as the inner conductor for feeding one portion (the lower portion) of the antenna array.
  • This intermediate conductive tubular member 35 also serves as the enclosing side wall of another transmission line for coupling radio frequency energy between the feed point and the associated radio frequency apparatus (not shown).
  • This additional transmission line may be coaxial, in which case and inner conductor 37 is surrounded by and is coaxial with the intermediate tubular member 35.
  • the transmission line for coupling the radio frequency energy to the slots in the other portion the upper portion) of the antenna is formed by the outer slotted cylinder 31 as the outer conductor and a tube 39 coaxial therewith as the inner conductor. Coupling of the two portions of the antenna array to the energy feed transmission line 35-37 is accomplished by connecting the inner conductor 37 of the feeder transmission line 3:5*37 to the tubular inner conductor 39 of the upper portion of the antenna. Since the intermediate tubular member 35 forms the other conductor of the energy feed transmission line 35-37, wave energy is introduced (or taken from) the adjacent ends of the intermediate tubular member 35 and the tube 39. The structure may, therefore, be considered as two lengths of energy distribution transmission line 31-39 and 31-35 connected in series with respect to the feed point.
  • the ends of the energy distribution transmission line 331-39 and 31-35 remote from the feed point were electrically connected together by means of metallic shorting blocks 43. While these shorting blocks 43 may be in the form of annular discs or the like, they are preferably made of a plurality of spoke members between the inner conductor 39 or 3S and the outer conductor 31 to allow the antenna to'be ventilated.
  • Each slot 33 is coupled to the interior of the energy distribution transmission line 31-35 and 31--39 by means of a coupling loop 41 having a reactance which is an integral part thereof.
  • a coupling loop 41 having a reactance which is an integral part thereof.
  • Such coupling loops for coupling radio frequency energy from a transmission line to a load are described and claimed in an application of Owen A. Fiet and Charles Polk, Serial No. 279,138, tiled March 28, 1952.
  • Such coupling loops may include a capacitive reactance or an inductive reactance arranged in series with the loop and forming an integral part thereof.
  • the coupling loop 41 associated with each individual slot is used to make the coupling device and the slot to which it is coupled appear as a load impedance of a desired magnitude and phase as considered from the transmission line 31-35 or 31-39.
  • the coupling loops in the longer portion were adjusted so that each one individually presented an impedance which, when taken together with the impedance presented by each of the other loops in the upper group, constituted one-half the impedance seen by the energy feed line 31, 37 at the feed point between the adjacent ends of the tubular members 35-39.
  • Each coupling loop 41 associated with the slots 33 in the shorter portion of the aperture was also adjustedy so that the total impedance presented by the slots 33 in the lower portion was the same as that of the upper portion.
  • An antenna feed system for an antenna array having a plurality of radiating elements occupying an aperture a plurality of wavelengths long comprising: a feed point for said radiating elements displaced from the electrical center of said aperture whereby the number of radiating elements on one side of said feed point is greater than the number of antenna elements on the other side of said feed point, and means coupling equal amounts of power to the two groups of elements either side of said feed point whereby an asymmetrical power distribution along the aperture of said antenna array is obtained.
  • An antenna feed system for an antenna array having a plurality of horizontally polarized antenna elements occupying a vertical aperture a plurality of wavelengths long comprising: a feed point for said antenna elements displaced from the physical center of said aperture, the number of antenna elements above said feed point being greater than the number of elements below said feed point, rst transmission line means coupling said feed point and all of the elements above said feed point, further transmission line means coupling said feed point coupling all of the elements below said feed point in equal degree to that of said first nsmission line means, whereby equal amounts of power are fed to the two groups of elements above and below said feed point.
  • An antenna feed system for antenna arrays which include a plurality of radiating elements occupying an aperture a plurality of wavelengths long comprising: a feed point for said antenna array displaced by more than 5% of the total aperture length from the physical and electrical center of said aperture, a first transmission line means from said feed point coupled to all of said plurality of antenna elements on one side of said feed point, said transmission line and said antenna elements coupled thereto having a predetermined impedance, second transmission line means from said feed point coupled to the remaining antenna elements on the other side of said feed point, said second transmission line means together with said antenna elements coupled thereto having the same said predetermined impedance, and means for coupling radio frequency apparatus to said first and second transmission lines at said feed point.
  • An antenna feed system for a slotted cylinder antenna having a plurality of longitudinal slots therein having a length a plurality of wavelengths long comprising: a tubular conductor coaxial with said slotted cylinder having each end connected to said slotted cylinder, said tubular conductor having an interruption therein intermediate the ends thereof to constitute a feed point for said antenna, said interruption being physically displaced by more than 5% of the total aperture length from the center of said antenna whereby the length of said antenna on one side of said feed point is greater than the length on the other side of said feed point, said slotted cylinder and said tubular conductor constituting transmission line means between said feed point and said slots, said transmission line means together with said slots coupled thereto having the same predetermined impedance to said feed point on either side of said feed point, said tubular conductor being hollow for at least the length of one of the portions formed by said interruption to effect the enclosing side wall of another transmission line, an additional conductor coaxial within and extending entirely through the hollow portion of said tubular conductor and having one end connected to
  • An antenna feed system for antenna arrays which include a plurality of horizontally polarized radiating elements occupying a vertical aperture a plurality of wavelengths long comprising: a feed point for said antenna. array displaced from the physical center of said aperture by a distance from 5% to 25% of the length of said aperture, a first transmission line means from said feed point coupled to all of said plurality of antenna elements on one side of said feed point, said transmission line and said antenna elements coupled thereto having a predetermined impedance, second transmission line means from said feed References Cited in the tile of this patent UNlTED STATES PATENTS 2,196,187 Blair Apr. 9, 1940 2,464,276 Varian Mar. l5, 1949 2,502,155 1950 2,658,143 Fiet et al. Nov. 3, 1953 OTHER REi-ERENCES Riblet: Microwave Omnidirectional Antennas, in Proc. IRE, vol. 35, No, 5, May 1947.

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  • Variable-Direction Aerials And Aerial Arrays (AREA)
US334142A 1953-01-30 1953-01-30 Antenna feed systems Expired - Lifetime US2744249A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
NLAANVRAGE7811702,A NL184706B (nl) 1953-01-30 Fotoelektrische toerentalmeetinrichting.
NL91730D NL91730C (de) 1953-01-30
FR1094683D FR1094683A (de) 1953-01-30
BE526052D BE526052A (de) 1953-01-30
US334142A US2744249A (en) 1953-01-30 1953-01-30 Antenna feed systems
GB1036/54A GB739618A (en) 1953-01-30 1954-01-13 Antenna feed systems
CH330332D CH330332A (de) 1953-01-30 1954-01-26 Antennenanlage
DER13474A DE1009678B (de) 1953-01-30 1954-01-30 Einrichtung zur Speisung einer Rohrschlitzantenne

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US334142A US2744249A (en) 1953-01-30 1953-01-30 Antenna feed systems

Publications (1)

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US2744249A true US2744249A (en) 1956-05-01

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US334142A Expired - Lifetime US2744249A (en) 1953-01-30 1953-01-30 Antenna feed systems

Country Status (7)

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US (1) US2744249A (de)
BE (1) BE526052A (de)
CH (1) CH330332A (de)
DE (1) DE1009678B (de)
FR (1) FR1094683A (de)
GB (1) GB739618A (de)
NL (2) NL184706B (de)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2947988A (en) * 1955-03-29 1960-08-02 Univ Ohio State Res Found Traveling wave antenna
US2971193A (en) * 1957-06-21 1961-02-07 Rca Corp Multiple slot antenna having radiating termination
US2973515A (en) * 1957-04-05 1961-02-28 Alford Andrew Omnidirectional vertically polarized antenna
US3321762A (en) * 1964-05-27 1967-05-23 Zucconi Bruno Slot antenna array useful with top mounted beacon light and decoupled internal powerline
US3638224A (en) * 1970-04-24 1972-01-25 Nasa Stacked array of omnidirectional antennas
US4297706A (en) * 1980-03-17 1981-10-27 Rca Corporation Circularly polarized slotted pylon antenna
FR2576692A1 (fr) * 1985-01-25 1986-08-01 Thomson Csf Systeme de radio-navigation du type vor doppler comportant un empilement central d'elements rayonnants
US4631544A (en) * 1985-04-10 1986-12-23 Tideland Signal Corporation S-band coaxial slot array antenna
WO2002061881A1 (en) * 2000-12-14 2002-08-08 General Signal Corporation Internally branch fed slotted coaxial antenna
EP2082493A1 (de) * 2006-11-14 2009-07-29 Telefonaktiebolaget LM Ericsson (PUBL) Antenne mit verbesserter strahlungscharakteristik
CN112054293A (zh) * 2020-10-21 2020-12-08 北京字节跳动网络技术有限公司 电子设备
US12080948B2 (en) 2021-04-21 2024-09-03 Skyworks Solutions, Inc. Staggered rows of antennas for dual frequency operation

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2927318A (en) * 1956-12-03 1960-03-01 Gen Dynamics Corp Radar system
US5809429A (en) * 1995-09-22 1998-09-15 Andrew Corporation Radiating coaxial cable and radio communication system using same
US6480163B1 (en) 1999-12-16 2002-11-12 Andrew Corporation Radiating coaxial cable having helically diposed slots and radio communication system using same
US8253636B2 (en) 2005-11-28 2012-08-28 Bae Systems Plc Improvements relating to antenna arrays
US10911076B2 (en) * 2016-12-28 2021-02-02 Sony Semiconductor Solutions Corporation Antenna device, communication device, and communication method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2196187A (en) * 1937-01-19 1940-04-09 William R Blair Directive antenna array
US2464276A (en) * 1943-08-03 1949-03-15 Sperry Corp Radiant energy directivity pattern scanner
US2502155A (en) * 1948-03-02 1950-03-28 Charles L Jeffers Low-angle radiation antenna
US2658143A (en) * 1950-03-16 1953-11-03 Rca Corp Ultrahigh-frequency broadcast antenna system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2196187A (en) * 1937-01-19 1940-04-09 William R Blair Directive antenna array
US2464276A (en) * 1943-08-03 1949-03-15 Sperry Corp Radiant energy directivity pattern scanner
US2502155A (en) * 1948-03-02 1950-03-28 Charles L Jeffers Low-angle radiation antenna
US2658143A (en) * 1950-03-16 1953-11-03 Rca Corp Ultrahigh-frequency broadcast antenna system

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2947988A (en) * 1955-03-29 1960-08-02 Univ Ohio State Res Found Traveling wave antenna
US2973515A (en) * 1957-04-05 1961-02-28 Alford Andrew Omnidirectional vertically polarized antenna
US2971193A (en) * 1957-06-21 1961-02-07 Rca Corp Multiple slot antenna having radiating termination
US3321762A (en) * 1964-05-27 1967-05-23 Zucconi Bruno Slot antenna array useful with top mounted beacon light and decoupled internal powerline
US3638224A (en) * 1970-04-24 1972-01-25 Nasa Stacked array of omnidirectional antennas
US4297706A (en) * 1980-03-17 1981-10-27 Rca Corporation Circularly polarized slotted pylon antenna
FR2576692A1 (fr) * 1985-01-25 1986-08-01 Thomson Csf Systeme de radio-navigation du type vor doppler comportant un empilement central d'elements rayonnants
US4631544A (en) * 1985-04-10 1986-12-23 Tideland Signal Corporation S-band coaxial slot array antenna
WO2002061881A1 (en) * 2000-12-14 2002-08-08 General Signal Corporation Internally branch fed slotted coaxial antenna
EP2082493A1 (de) * 2006-11-14 2009-07-29 Telefonaktiebolaget LM Ericsson (PUBL) Antenne mit verbesserter strahlungscharakteristik
US20100053024A1 (en) * 2006-11-14 2010-03-04 Andersson Mats H Antenna with an improved radiation pattern
EP2082493A4 (de) * 2006-11-14 2011-07-27 Ericsson Telefon Ab L M Antenne mit verbesserter strahlungscharakteristik
CN112054293A (zh) * 2020-10-21 2020-12-08 北京字节跳动网络技术有限公司 电子设备
CN112054293B (zh) * 2020-10-21 2023-03-24 北京字节跳动网络技术有限公司 电子设备
US12080948B2 (en) 2021-04-21 2024-09-03 Skyworks Solutions, Inc. Staggered rows of antennas for dual frequency operation

Also Published As

Publication number Publication date
NL184706B (nl)
FR1094683A (de) 1955-05-23
DE1009678B (de) 1957-06-06
GB739618A (en) 1955-11-02
NL91730C (de)
CH330332A (de) 1958-05-31
BE526052A (de)

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