US3771160A - Radio aerial - Google Patents

Radio aerial Download PDF

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Publication number
US3771160A
US3771160A US00168556A US3771160DA US3771160A US 3771160 A US3771160 A US 3771160A US 00168556 A US00168556 A US 00168556A US 3771160D A US3771160D A US 3771160DA US 3771160 A US3771160 A US 3771160A
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United States
Prior art keywords
reflector
plane
wave
assembly
parallel
Prior art date
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Expired - Lifetime
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US00168556A
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English (en)
Inventor
E Laverick
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.)
Allard Way Holdings Ltd
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Elliott Brothers London Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R12/00—Structural associations of a plurality of mutually-insulated electrical connecting elements, specially adapted for printed circuits, e.g. printed circuit boards [PCB], flat or ribbon cables, or like generally planar structures, e.g. terminal strips, terminal blocks; Coupling devices specially adapted for printed circuits, flat or ribbon cables, or like generally planar structures; Terminals specially adapted for contact with, or insertion into, printed circuits, flat or ribbon cables, or like generally planar structures
    • H01R12/70—Coupling devices
    • H01R12/7082—Coupling device supported only by cooperation with PCB
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
    • H01Q19/10—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces
    • H01Q19/18—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces
    • H01Q19/19—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces comprising one main concave reflecting surface associated with an auxiliary reflecting surface
    • H01Q19/195—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces having two or more spaced reflecting surfaces comprising one main concave reflecting surface associated with an auxiliary reflecting surface wherein a reflecting surface acts also as a polarisation filter or a polarising device
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
    • H01Q5/40—Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
    • H01Q5/45—Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements using two or more feeds in association with a common reflecting, diffracting or refracting device

Definitions

  • ABSTRACT [30] Foreign Application Priority Data A l h f d T cassegrain aeria aving a primary ee an auxi obviouslyy 1970
  • Great Bmam 37684/70 reflector which transmits or reflects according to the plane of polarisation of energy incident on it from the [52] us Cl 343/756 343/781 347 primary feed, and a main, twist reflector which receives Int Cl H01 19/00 energy reflected from the auxiliary reflector, rotates its Field 909 plane through 90 and re-reflects it into free space 343/781 837 through the intervening auxiliary reflector.
  • twist reflector consists of a sheet reflector in front of which two, parallel, wire grids are arranged, the wires [56] Reiereuces Cited extending at 45 to the plane of the incident wave and UNITED STATES PATENTS being arranged so that 90 rotation of the polarisation 3,569,980 3/1971 Salmon 343/909 plane is effected at at least two frequencies. 2,736,895 2/1956 Cochrane 343/756 3,161,879 12/1964 l-lannan et al. 343/756 X 5 Claims, 3 Drawing Figures RAnio AERIAL This invention relates to radio aerials and particularly to such aerials which employ plane polarised radio waves for producing selective reflection and transmission at certain surfaces.
  • An object of the present invention is to provide means in a radio aerial for producing a rotational shift of the plane of polarisation of an incident plane polarised wave' for at least two frequencies of incident wave.
  • the assembly comprises a plurality of conductive grids arranged in front of a reflector, the admittance of the individual grids, and the spacing between the grids and between the grids and the reflector, being such that, at each of a plurality of operating frequencies, the respective admittances of the assembly to mutually perpendicular components of a predetermined plane polarised wave incident upon the assembly are of relatively inverse magnitude and opposite sign.
  • One of the two grids may be spaced from the reflector approximately a quarter wavelength in respect of a first predetermined-frequency and the second grid positioned in the region of a short circuit position with respect to the input admittance presented to an incident wave of that first frequency.
  • the reflector assembly may comprise, in conjunction, a plane metal reflector, a layer of dielectric foam material, a first grid of parallel wires, a second layer of dielectric foam material and a second grid of parallel wires, the wires of each grid being glued to a respective dielectric skin which is glued to the adjacent foam layer.
  • a cassegrain radar aerial comprises a localised source of a plane polarised wave, the source being directed at an auxiliary reflector comprising an array of conductors extending in a direction parallel to the electric plane of said polarised wave, and a twist reflector assembly including a plane reflector, a first grid of parallel conductors spaced a quarter wavelength from the plane reflector in respect of a first predetermined frequency, and a second grid of parallel conductors situated in the region of a short circuit position with respect to the input admittance, at said first predetermined frequency, presented, in operation, to a plane polarised wave reflected from said auxiliary reflector and incident upon the twist reflector assembly, the conductors of the two grids extending in a direction which is at 45 to the plane of polarisation of the wave incident at said twist reflector assembly, and the individual admittances of the two grids being such that a plane polarised wave, of said first or a second predetermined frequency, originating from said
  • FIG. 1 is a diagrammatic view of a section of the aerial in a plane containing the aerial axis
  • FIG. 2 is a part sectional view of a detail, a twist reflector assembly, of FIG. 1, and
  • FIG. 3 shows equivalent circuits for the twist reflector assembly of FIG. 2 in respect of orthogonal components of an incident wave.
  • a feed horn 1 is directed at a parabolic reflector 2 and is positioned at the focus of the reflector 2 so that the wave reflected by the reflector 2 is a parallel beam.
  • the wave emitted by the feed horn l is plane polarised, the electric (E) vector being perpendicular to the plane of the paper.
  • the parabolic reflector 2 functions also as a transparent window in accordance with the angle of the plane of polarisation of a wave incident upon it. It is constructed of a number of parallel conducting strips 3 shown in end view in FIG. 1. At least the leading edge of each strip 3 is shaped to conform to the paraboloidal surface of thereflector 2 as a whole.
  • the strips 3 are embedded in a dielectric medium, for example a fibreglass honeycomb, and a dielectric skin glued to the front and back faces may be used to increase the rigidity of the structure.
  • Parallel wires may be used instead of the strips 3.
  • the spacing of the conductors must be sufficiently small to give a high reflection coefficient at the highest operating frequency and their thickness (diameter) must be sufficiently small to give high transmission of energy polarised perpendicular to them.
  • the E vector of the waveemitted by the feed horn 11 is polarised perpendicular to the plane of the paper, and, as can be seen in FIG. ll, this is in alignment with the direction of the strips 3. Nearly complete reflection therefore results and a parallel beam is reflected to a twist reflector assembly 45.
  • this twist reflector assembly is required to twist the plane of polarisation of the wave incident upon it.
  • a 90 twist of this plane causes the wave reflected by the twist reflector 4 to be polarisedin a plane parallel to the plane of the paper and thus transverse to the strips 3 of the reflector 2. Substantially complete transmission of the wave by the reflector 2 then occurs.
  • the twist reflector 4 is pivotally mounted about an axis (not shown) perpendicular to the plane of the paper. It will be apparent that the angular sweep of the beam is twice the angular displacement of the twist reflector 4.
  • twist reflector 4 The construction and operation of the twist reflector 4 will now be described.
  • FIG. 2 which is not to scale, shows two copper wire grids and 6 mounted in front of a continuous aluminium back plate 7.
  • the distances D1 and D2 between the plane 7 the grid 5 and the grid 6 are determined as will be explained.
  • the spacing of the individual wires 8 and 9 of the grids must be sufficiently small to permit satisfactory reflection while at the same time this spacing in conjunction with the wire diameter is chosen to produce a desired grid impedance.
  • Each grid 5 and 6 is formed by sticking the wires to a skin.
  • the skins are then gluedto low-density dielectric foam sheets 1 l which maintain the spacings D1 and D2.
  • the rear foam sheet 11 is also glued to the aluminium plate 7.
  • the operation of the twist reflector 4 depends upon the production of a differential phase shift between different components of an incident plane polarised wave.
  • the grids are accordingly arranged with the wires 8 and 9 at 45 to the plane of polarisation of an incident wave.
  • the upper circuit shows the transmission line equivalent of the twist reflector 4 as presented to the parallel component of the E field of the incident wave.
  • the lower circuit shows the corresponding equivalent transmission line for the perpendicular component.
  • the diagrams at the left indicate the field component in relation to the grid wires.
  • the grids 5 and 6 constitute inductive shunts across the line, while for the perpendicular components the grids 5 and 6 constitute capacitive shunts.
  • the grids are shunted by a small capacitance resulting from the dielectric skin on which the wires are mounted. This error capacitance is compensated by a corresponding small increase in the grid inductance beyond the calculated value.
  • the grid 5 is first positioned to provide operation at one frequency, that is, it is positioned a quarter wavelengh, at that frequency, in front of the back plate 7 with the wires 8 of the grid arranged at 45 to the plane of polarisation of the incident wave.
  • the grid 6 is then positioned at the first (or another) short circuit plane (at the first chosen frequency) in the path to the grid 5 and back plate 7 so that, being in parallel with a short circuit, i.e., an infinite admittance, the admittance of the grid 6 has no effect at this chosen frequency. There is then complete freedom to adjust the diameter and spacing of the wires 9 of the grid 6 to achieve, at various lower frequencies, the necessary inverse parallel and perpendicular admittance relation previously mentioned in conjunction with the first grid.
  • the position of the second grid 6 can be varied to some extent, at the higher frequency without unduly affecting the higher frequency condition. This is because, as can be seen by reference to a Smith Chart, for a limited distance on either side of the infinite admittance (short circuit) plane the admittance remains sufficiently large to swamp the transferred admittance of the second grid 6.
  • the form of dual frequency design in which first one grid is positioned for the high frequency and then a second grid is added for the low frequency, can have a wide bandwidth for both low and high frequencies. It is applicable when the two frequencies are in odd harmonic relation, i.e.
  • Ratio ranges corresponding to the 2 to 5 variation of the third harmonic relation exist for other pairs in the above odd harmonic series, for example for the pairs 1:7; 1:9 etc., although the greater the pair ratio the smaller the possible variation of the ratio.
  • a pair of grids is positioned, according to the above design, to operate at the highest two frequencies, then a third grid is added, in the region of a short circuit plane, which operates at the next lower frequency but has no effect on the upper two frequencies. Further grids may be added similarly.
  • This design provides operating frequencies in the ratio 1:329:27 etc.
  • allel to said plane reflector member for intercepting a wave incident upon said plane reflector member, said grids having individual admittances and spacings from said reflector member for providing that, at each one of a plurality of distinct operating frequencies, the respective admittances of said reflector assembly, to components of said wave parallel to said conductors and perpendicular to said conductors, are of relatively inverse magnitude and opposite sign.
  • said reflector assembly comprises, in order, a plane metal reflector member, a first layer of dielectric foam material, a first grid assembly comprising a first dielectric skin member and a plurality of parallel wires glued to said first dielectric skin member, a second layer of dielectric foam material, and a second grid assembly comprising a second dielectric skin member and a plurality of parallel wires glued to said second dielectric skin member, said plane metal reflector member, said layers of dielectric foam material and said grid assemblies being glued together to form a unitary assembly.
  • a cassegrain radar aerial comprising a localised source of a plane polarised wave, an auxiliary reflector at which said localised source is directed, said auxiliary reflector comprising an array of parallel conductors extending parallel to the electric component of a plane polarised wave received from said localised source, said reflector assembly being directed toward said auxiliary reflector for rotating the plane of polarisation of a wave derived from said source by reflection from said auxiliary reflector, and for reflecting the wave so derived to said auxiliary reflector for transmission therethrough.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Aerials With Secondary Devices (AREA)
  • Waveguide Aerials (AREA)
US00168556A 1970-08-04 1971-08-03 Radio aerial Expired - Lifetime US3771160A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3768470 1970-08-04

Publications (1)

Publication Number Publication Date
US3771160A true US3771160A (en) 1973-11-06

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US (1) US3771160A (enExample)
DE (1) DE2139076C2 (enExample)
FR (1) FR2101220B1 (enExample)
GB (1) GB1330175A (enExample)

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4178574A (en) * 1977-01-12 1979-12-11 U.S. Philips Corporation Horn antenna with rotating waveguide and polarization lens means
EP0015837A3 (fr) * 1979-03-09 1980-10-01 Thomson-Csf Antenne à plans parallèles à rotation de polarisation
US4253100A (en) * 1979-02-02 1981-02-24 Thomson-Csf Inverse cassegrain antenna for multiple function radar
US4298876A (en) * 1979-03-02 1981-11-03 Thomson-Csf Polarizer for microwave antenna
US4335387A (en) * 1979-06-13 1982-06-15 Thomson-Csf Radar antenna with rotating linear polarization designed to reduce jamming
US4435714A (en) 1980-12-29 1984-03-06 Ford Aerospace & Communications Corp. Grating lobe eliminator
US4504835A (en) * 1982-06-15 1985-03-12 The United States Of America As Represented By The Secretary Of The Navy Low sidelobe, high efficiency mirror antenna with twist reflector
US4574287A (en) * 1983-03-04 1986-03-04 The United States Of America As Represented By The Secretary Of The Navy Fixed aperture, rotating feed, beam scanning antenna system
US4599623A (en) * 1982-07-15 1986-07-08 Michael Havkin Polarizer reflector and reflecting plate scanning antenna including same
US4668957A (en) * 1983-10-12 1987-05-26 Gesellschaft f/u/ r Schwerionenforschung mbH Darmstadt Amorphous glass matrix containing aligned microscopically thin metal conductors
EP0091343B1 (fr) * 1982-04-02 1987-07-22 Thomson-Csf Antenne Cassegrain inversée pour radar à fonction multiple
FR2596208A1 (fr) * 1986-03-19 1987-09-25 Europ Agence Spatiale Antenne bifrequence a faisceaux orientables independants
US4786914A (en) * 1985-01-25 1988-11-22 E-Systems, Inc. Meanderline polarization twister
US4977407A (en) * 1981-07-23 1990-12-11 Crane Patrick E Optical collimator
US5003321A (en) * 1985-09-09 1991-03-26 Sts Enterprises, Inc. Dual frequency feed
US5202701A (en) * 1991-07-23 1993-04-13 Grumman Aerospace Corporation Low radar cross section reflector antenna
US5319379A (en) * 1984-08-24 1994-06-07 Hercules Defense Electronics Systems, Inc. Parabolic dual reflector antenna with offset feed
WO1998049750A1 (en) * 1997-04-29 1998-11-05 Era Patents Limited Twist reflector antenna
US6307522B1 (en) * 1999-02-10 2001-10-23 Tyco Electronics Corporation Folded optics antenna
US20030227417A1 (en) * 2002-01-17 2003-12-11 English Errol K. Electromagnetic-field polarization twister
WO2020030952A1 (en) 2018-08-08 2020-02-13 Nokia Shanghai Bell Co., Ltd Antenna

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4471359A (en) * 1982-06-15 1984-09-11 The United States Of America As Represented By The Secretary Of The Navy Dual band, low sidelobe, high efficiency mirror antenna
DE19713735C1 (de) * 1997-04-03 1998-08-20 Daimler Benz Aerospace Ag Verfahren zur Herstellung von polarisationsselektiven Reflektoren

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2736895A (en) * 1951-02-16 1956-02-28 Elliott Brothers London Ltd High frequency radio aerials
US3161879A (en) * 1961-01-05 1964-12-15 Peter W Hannan Twistreflector
US3271771A (en) * 1962-02-15 1966-09-06 Hazeltine Research Inc Double-reflector, double-feed antenna for crossed polarizations and polarization changing devices useful therein
US3340535A (en) * 1964-06-16 1967-09-05 Textron Inc Circular polarization cassegrain antenna
US3448455A (en) * 1964-03-20 1969-06-03 Thomson Houston Comp Francaise Armoured structure antenna
US3560984A (en) * 1968-12-11 1971-02-02 Loral Corp Broadband circularly polarized antenna having a continuous rectangular aperture
US3569980A (en) * 1967-05-16 1971-03-09 Thomson Csf Polarizer network

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE37C (de) * 1877-07-12 A. SlEMROTH zu Böhlen, Schwarzburg - Rudolstadt Beweglicher Parketboden nebst Fugenschlofs
US3281850A (en) * 1962-03-07 1966-10-25 Hazeltine Research Inc Double-feed antennas operating with waves of two frequencies of the same polarization

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2736895A (en) * 1951-02-16 1956-02-28 Elliott Brothers London Ltd High frequency radio aerials
US3161879A (en) * 1961-01-05 1964-12-15 Peter W Hannan Twistreflector
US3271771A (en) * 1962-02-15 1966-09-06 Hazeltine Research Inc Double-reflector, double-feed antenna for crossed polarizations and polarization changing devices useful therein
US3448455A (en) * 1964-03-20 1969-06-03 Thomson Houston Comp Francaise Armoured structure antenna
US3340535A (en) * 1964-06-16 1967-09-05 Textron Inc Circular polarization cassegrain antenna
US3569980A (en) * 1967-05-16 1971-03-09 Thomson Csf Polarizer network
US3560984A (en) * 1968-12-11 1971-02-02 Loral Corp Broadband circularly polarized antenna having a continuous rectangular aperture

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4178574A (en) * 1977-01-12 1979-12-11 U.S. Philips Corporation Horn antenna with rotating waveguide and polarization lens means
EP0014605B1 (fr) * 1979-02-02 1983-02-23 Thomson-Csf Antenne Cassegrain inversée pour radar à fonctions multiples
US4253100A (en) * 1979-02-02 1981-02-24 Thomson-Csf Inverse cassegrain antenna for multiple function radar
US4298876A (en) * 1979-03-02 1981-11-03 Thomson-Csf Polarizer for microwave antenna
EP0015837A3 (fr) * 1979-03-09 1980-10-01 Thomson-Csf Antenne à plans parallèles à rotation de polarisation
FR2451114A1 (fr) * 1979-03-09 1980-10-03 Thomson Csf Antenne a plans paralleles a rotation de polarisation
US4297710A (en) * 1979-03-09 1981-10-27 Thomson-Csf Parallel-plane antenna with rotation of polarization
US4335387A (en) * 1979-06-13 1982-06-15 Thomson-Csf Radar antenna with rotating linear polarization designed to reduce jamming
US4435714A (en) 1980-12-29 1984-03-06 Ford Aerospace & Communications Corp. Grating lobe eliminator
US4977407A (en) * 1981-07-23 1990-12-11 Crane Patrick E Optical collimator
EP0091343B1 (fr) * 1982-04-02 1987-07-22 Thomson-Csf Antenne Cassegrain inversée pour radar à fonction multiple
US4504835A (en) * 1982-06-15 1985-03-12 The United States Of America As Represented By The Secretary Of The Navy Low sidelobe, high efficiency mirror antenna with twist reflector
US4599623A (en) * 1982-07-15 1986-07-08 Michael Havkin Polarizer reflector and reflecting plate scanning antenna including same
US4574287A (en) * 1983-03-04 1986-03-04 The United States Of America As Represented By The Secretary Of The Navy Fixed aperture, rotating feed, beam scanning antenna system
US4668957A (en) * 1983-10-12 1987-05-26 Gesellschaft f/u/ r Schwerionenforschung mbH Darmstadt Amorphous glass matrix containing aligned microscopically thin metal conductors
US5319379A (en) * 1984-08-24 1994-06-07 Hercules Defense Electronics Systems, Inc. Parabolic dual reflector antenna with offset feed
US4786914A (en) * 1985-01-25 1988-11-22 E-Systems, Inc. Meanderline polarization twister
US5003321A (en) * 1985-09-09 1991-03-26 Sts Enterprises, Inc. Dual frequency feed
FR2596208A1 (fr) * 1986-03-19 1987-09-25 Europ Agence Spatiale Antenne bifrequence a faisceaux orientables independants
US5202701A (en) * 1991-07-23 1993-04-13 Grumman Aerospace Corporation Low radar cross section reflector antenna
WO1998049750A1 (en) * 1997-04-29 1998-11-05 Era Patents Limited Twist reflector antenna
US6307522B1 (en) * 1999-02-10 2001-10-23 Tyco Electronics Corporation Folded optics antenna
US20030227417A1 (en) * 2002-01-17 2003-12-11 English Errol K. Electromagnetic-field polarization twister
US6906685B2 (en) 2002-01-17 2005-06-14 Mission Research Corporation Electromagnetic-field polarization twister
WO2020030952A1 (en) 2018-08-08 2020-02-13 Nokia Shanghai Bell Co., Ltd Antenna
EP3830902A4 (en) * 2018-08-08 2022-03-16 Nokia Shanghai Bell Co., Ltd. ANTENNA
US11605898B2 (en) * 2018-08-08 2023-03-14 Nokia Shanghai Bell Co., Ltd. Antenna

Also Published As

Publication number Publication date
DE2139076A1 (de) 1972-02-10
FR2101220A1 (enExample) 1972-03-31
GB1330175A (en) 1973-09-12
FR2101220B1 (enExample) 1976-09-03
DE2139076C2 (de) 1982-08-26

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