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WO1992008254A1 - Procede de fabrication de lentilles a indice de refraction variable - Google Patents

Procede de fabrication de lentilles a indice de refraction variable Download PDF

Info

Publication number
WO1992008254A1
WO1992008254A1 PCT/EP1991/001981 EP9101981W WO9208254A1 WO 1992008254 A1 WO1992008254 A1 WO 1992008254A1 EP 9101981 W EP9101981 W EP 9101981W WO 9208254 A1 WO9208254 A1 WO 9208254A1
Authority
WO
WIPO (PCT)
Prior art keywords
refraction index
lens
lenses
produced
thread
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.)
Ceased
Application number
PCT/EP1991/001981
Other languages
English (en)
Inventor
Gerhard Maier
David Harrison
Masahiro Fujimoto
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.)
Vantiva SA
Technicolor USA Inc
Original Assignee
Thomson Consumer Electronics SA
Thomson Consumer Electronics 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 Thomson Consumer Electronics SA, Thomson Consumer Electronics Inc filed Critical Thomson Consumer Electronics SA
Priority to JP3516866A priority Critical patent/JPH06502052A/ja
Priority to US08/080,390 priority patent/US5421848A/en
Priority to EP91918271A priority patent/EP0555262B1/fr
Priority to DE69103764T priority patent/DE69103764T2/de
Priority claimed from AU87835/91A external-priority patent/AU630329B3/en
Publication of WO1992008254A1 publication Critical patent/WO1992008254A1/fr
Anticipated expiration legal-status Critical
Priority to HK13797A priority patent/HK13797A/en
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/23—Combinations of reflecting surfaces with refracting or diffracting devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q15/00—Devices for reflection, refraction, diffraction or polarisation of waves radiated from an antenna, e.g. quasi-optical devices
    • H01Q15/02—Refracting or diffracting devices, e.g. lens, prism

Definitions

  • the invention relates to a method for the fabrication of three-dimensional lenses with a variable refraction index.
  • Lenses with a variable refraction index such as a Luneburg lens or a Eaton-Lippmann lens
  • a variable refraction index such as a Luneburg lens or a Eaton-Lippmann lens
  • lenses with variable refraction indexes can be used as radar reflectors or, as is known from E. F. Buckley; "Stepped-Index Luneburg Lenses"; Electronic Design, ApriL, 13, 1960, as part of an antenna system.
  • the Layers for the fabrication of Luneburg and Eaton-Lippmann lenses can be produced by mixed dielectrics.
  • a mixed dielectric can be obtained by mixing expanded particles selected from the group consisting of expanded polystorols, expanded polyethylenes, expanded polyuret hanes, glass balloons and silica balloons, with metal-coated particles consisting of said expanded particles, surfaces of which have been coated with a thin film selected from the group of chromium, aluminium, copper, nickel, gold, silver, and magnesium in proper proportions to obtain a desired dielectric constant then forming the same to the desired shape by the use of a binder.
  • the method according to the invention allows to produce three-dimensional lenses with a variable refraction index n by wrapping a material with a given refraction index, e.g such as the known materials from US 4 288 337, into the final shape of the lens to be produced.
  • a material with a given refraction index e.g such as the known materials from US 4 288 337
  • the method for the fabrication can be executed more easiIy.
  • Fig 1 shows a known Luneburg lens radar reflector
  • Fig 2 shows a known Luneburg lens antenna
  • Fig 3 shows a preferred embodiment
  • Fig 4a, b show possible shapes of thread used.
  • the lenses to be produced are able to refract electromagnetic waves, preferably microwaves.
  • the material with a given refraction index n is a dielectric material and the refraction index n is given by the expression
  • Fig. 1 shows a three-dimensional Luneburg lens 10, which works as radar reflector and as is state of the art.
  • An incoming wave 11 is focussed by the lens 10 in such a way that the wave is focussed on a focus point 12.
  • the wave is reflected by a reflector 13, whereby the reflected wave 14 is generated, which is led by the lens 10 in such a way, that it leaves the lens 10 in the same direction as the incoming wave 11 came from.
  • a is the radius of the lens
  • r/a 1.0 at the outer surface of the lens.
  • Fig. 2 shows another application of the Luneburg lens 10.
  • an incoming wave such as 11a is led to a first focus point 12a and received by a first feeder horn 20a.
  • incoming waves 11b and 11c are led to focus points 12b, 12c and received by feeder horns 20 b, 20c respectively.
  • the signals received by the feeder horns 20a, 20b, 20c are led to not shown receivers.
  • system according to fig. 2 can also work as transmitter antenna, if transmitters are connected to the feeder horns 20a, 20b, 20c.
  • the three-dimensional lens 10 is produced by wrapping a dielectric material, preferably shaped as a thread. This is in principle shown in fig.3.
  • the effective relative dielectric constant may be varied by a variation of the relative dielectric constant E of the thread. This could be achieved e.g. by a variation of the chemical composition or by a variation of the density of said thread with length. A variation of density with length could be achieved e.g. by a variation of pressure, proceeded by a press arranged before the lens 10' to be produced.
  • a crimped thread e.g. like it is shown in fig. 4a or 4b, which might be stretched by a variation of a stretching force used.
  • the dielectric constant of the thread may also be varied along the length with the aid of a metallic paint.
  • a low density dielectric thread of constant dielectric constant is used and as it is wrapped into the shape of the lens to be produced small areas of the thread are painted at a separation necessary to give the correct dielectric constant profile. That means for a desired value of the effective refraction index the thread used is painted with a paint, which may be metallic. Thickness, density or/a n d intensity of this paint may be varied. This is a simple method and will result in a relatively light lens.
  • the material with the given refraction index may have any other appropriate shape, e.g. Like a strip, ribbon, or the like
  • the lens to be produced may be able to refract other electromagnetic waves, such as visible or infrared light.
  • other electromagnetic waves such as visible or infrared light.
  • lenses with non- spherical shapes may be produced,
  • the lens to be produced may have any desired relation
  • the wrapping process may start at the surface of a core, which itself might have a variation of the refraction index and might be located around the center point,
  • a bonding agent may be used, which e.g. might be wrapped with the dielectric thread and when cured at an elevated temperature forms a more solid lens. of course, it might also be possible to dip the lens to be produced into an appropriate bonding agent during or/and after the wrapping process.
  • the invention presents a method for the fabrication or production of three-dimensional lenses with a variable effective refraction index by wrapping a material with a given refraction index, which may be constant or may vary with length. It is preferred, that said material has the shape of a thread, which might be cylindrical.
  • the preferred shapes of the lens to be produced are spherical or semi-spherical. The latter one can be achieved by an appropriate wrapping process or by cutting the spherical shape.

Landscapes

  • Aerials With Secondary Devices (AREA)

Abstract

Procédé de fabrication ou de production de lentilles tridimensionnelles à indice de réfraction variable, consistant à envelopper un matériau qui présente un indice de réfraction fixe. De préférence, ce matériau a la forme d'un fil éventuellement cylindrique. La forme préférée de la lentille est sphérique ou semi-sphérique, et on l'obtient à l'aide d'un procédé approprié d'enveloppement ou en taillant. Grâce à ce procédé, on peut produire des lentilles dont l'indice de réfraction varie de manière égale. De préférence, on utilise ces lentilles dans un système d'antennes hyperfréquences.
PCT/EP1991/001981 1990-10-29 1991-10-18 Procede de fabrication de lentilles a indice de refraction variable Ceased WO1992008254A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP3516866A JPH06502052A (ja) 1990-10-29 1991-10-18 可変屈折率レンズの製造方法
US08/080,390 US5421848A (en) 1990-10-29 1991-10-18 Method for fabricating a lens having a variable refractive index
EP91918271A EP0555262B1 (fr) 1990-10-29 1991-10-18 Procede de fabrication de lentilles a indice de refraction variable
DE69103764T DE69103764T2 (de) 1990-10-29 1991-10-18 Verfahren zur herstellung von linsen mit variabelem brechungsindex.
HK13797A HK13797A (en) 1990-10-29 1997-02-05 Method for the fabrication of lenses with a variable refraction index

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
EP90403051 1990-10-29
EP90403051.7 1990-10-29
AU87835/91A AU630329B3 (en) 1991-11-13 1991-11-13 Gas control valve

Publications (1)

Publication Number Publication Date
WO1992008254A1 true WO1992008254A1 (fr) 1992-05-14

Family

ID=25640934

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1991/001981 Ceased WO1992008254A1 (fr) 1990-10-29 1991-10-18 Procede de fabrication de lentilles a indice de refraction variable

Country Status (1)

Country Link
WO (1) WO1992008254A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000076027A1 (fr) * 1999-06-07 2000-12-14 Spike Broadband Systems, Inc. Lentilles a gradient symetrique sur le plan axial et systemes d'antennes correspondants
EP1093201A1 (fr) * 1999-10-13 2001-04-18 THOMSON multimedia Enrouleur de câbles et dispositif de communication par ondes électromagnétiques équipé d'un tel enrouleur
ES2156756A1 (es) * 1999-09-30 2001-07-01 Arranz Gil Jose Luis Procedimiento de fabricacion manual de lentes esfericas.

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3307196A (en) * 1962-12-28 1967-02-28 Armstrong Cork Co Luneberg type lens formed by spiral winding elongated strip of variable dielectric constant material
US4288337A (en) * 1977-05-02 1981-09-08 Tokyo Keiki Company Limited Lightweight materials having a high dielectric constant and their method of manufacture
US4482513A (en) * 1981-03-10 1984-11-13 General Dynamics, Pomona Division Method of molding foam/aluminum flake microwave lenses

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3307196A (en) * 1962-12-28 1967-02-28 Armstrong Cork Co Luneberg type lens formed by spiral winding elongated strip of variable dielectric constant material
US4288337A (en) * 1977-05-02 1981-09-08 Tokyo Keiki Company Limited Lightweight materials having a high dielectric constant and their method of manufacture
US4482513A (en) * 1981-03-10 1984-11-13 General Dynamics, Pomona Division Method of molding foam/aluminum flake microwave lenses

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000076027A1 (fr) * 1999-06-07 2000-12-14 Spike Broadband Systems, Inc. Lentilles a gradient symetrique sur le plan axial et systemes d'antennes correspondants
ES2156756A1 (es) * 1999-09-30 2001-07-01 Arranz Gil Jose Luis Procedimiento de fabricacion manual de lentes esfericas.
EP1093201A1 (fr) * 1999-10-13 2001-04-18 THOMSON multimedia Enrouleur de câbles et dispositif de communication par ondes électromagnétiques équipé d'un tel enrouleur
US6595452B1 (en) 1999-10-13 2003-07-22 Thomson Licensing, S.A. Cable reel and electromagnetic wave communication device equipped with such a reel

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