US2415352A - Lens for radio-frequency waves - Google Patents

Lens for radio-frequency waves Download PDF

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Publication number
US2415352A
US2415352A US532381A US53238144A US2415352A US 2415352 A US2415352 A US 2415352A US 532381 A US532381 A US 532381A US 53238144 A US53238144 A US 53238144A US 2415352 A US2415352 A US 2415352A
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United States
Prior art keywords
lens
wave
waves
radio
ultra high
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Expired - Lifetime
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US532381A
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English (en)
Inventor
Harley A Iams
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
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Filing date
Publication date
Priority to BE474864D priority Critical patent/BE474864A/xx
Application filed by RCA Corp filed Critical RCA Corp
Priority to US532381A priority patent/US2415352A/en
Priority to GB10213/45A priority patent/GB608949A/en
Application granted granted Critical
Publication of US2415352A publication Critical patent/US2415352A/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
    • 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

  • FIG. 10 is a sectional view of Patented Feb. 4, 1947 STATES i 2,415,352 Y Lens Foa RADIO-FREQUENCY WAVES Harley A. Iams, Princeton,
  • 'I'his invention relates to lenses for radio frequency waves and more particularly to such lenses in which the wave reflections from the surfaces are reduced.
  • radio frequency waves may be reflected and refracted. Reflections or refractions of radio waves occur when a wave travelling through a medium'reaches a, discontinuity in the medium or goes from one medium into another in which its velocity is different. If the surface or object in the path of the wave is composed of non-conductive material, both reflection and transmission with refraction may occur depending upon the angle between the direction of propagation and the reflecting surface, and upon other factors which do not require discussion here.
  • Lenses for focusing radio frequency waves have been made of materials such as pitch, paran-ln, and other insulators.
  • the abrupt change from the dielectric constant of the medium of propagation to the dielectric constant of the lens produces an undesired reflection of the waves.
  • the instant invention relates to the reduction of such undesired reflections.
  • One of the objects of the invention is to provide means for reducing the undesired reflection from the surface of a radio frequency lens. Another object is to provide an improved lens for radio waves of ultra high frequency. Another object is to provide a lens including reflection reducing surfaces whereby radio waves will be transmitted with less loss. An additional object is to provide an improved lens with a skeletonized surface for minimizing the reflection of radio frequency waves.
  • Figs. 1 and 2 y are plan and section views, respectively, of one embodiment of theinvention
  • Figs. 3 and 4 are plan and section views, respectively, of a radio conductive members
  • Figs. 5 and 6 are plan and section views, respectively, of a biconvex lens including reflection reducing coatings
  • Figs. 7, 8 and 9 are plan, section views and a detailed section view, respectively, of a biconvex lens including a skeletonized a modification of the invention.
  • a lens including a flat core I of wave refracting material such as Micalex is constructed with one curved surface 3 and one plane surface 5.
  • the core material has a dielectric constant of 6.1.
  • Coatings '7 and 9, consisting of Lucite or polystyrene having a thickness 0f approximately one quarter wave length in the coating material, are cemented or otherwise secured to the effective surfaces 3, 5 of the lens.
  • the dielectric constant of the coating material should be the square root of that of the core material; since the dielectric constant of polystyrene is 2.5, it is well suited for coating MicaleX. .In the case of the described lens, a substantial increase in transmission and a substantial reduction in undesired reflections were observed when radio waves of a frequency of 24,000 megacycles were applied. The image appears in the focal line represented by the dash line I I.
  • the lens described in the foregoing paragraph was inserted between a pair of conductive sheets I3, I5, preferably spaced by 1/2 wavelength or less.
  • the sheets may be curved to form an aperture Il which may be disposed otherwise than in geometric alignmentwith the effective surface 'I of the lens.
  • the conductive sheets guide the radio waves toward the lens and from the lens to the focal line II.
  • the lens may be used for transmission by applying the wave energy at the open end of the sheets which may be shaped or bent to conform to the focal line.
  • a lens I9 was formed of Micalex.
  • the following dimensions are given by way of example rather than limitation: diameter 14 inches, radius of each face 40 inches, and focal length 13 inches.
  • and 23 should be made of an insulator having a dielectric constant of the order of 2.5 and a thickness substantially equal to a quarter wave length of the applied radio frequency waves as measured in the insulator. Since this thickness of the reflection reducing coatings is based upon normal incidence, it follows that the coating will not minimize rreflections at all angles.
  • the ideal thickness is somewhat greater, being cos 0 where E is the dielectric constant of the material.
  • E is the dielectric constant of the material.
  • Another method of reducing the reection is to avoid abrupt changes in dielectric constants.
  • the reflection may be reduced by tapering the effective surface as shown in Fig. 10.
  • A2 wave length in air
  • 7q wave length in material of lens
  • p. index of refraction of material
  • a any integer.
  • reection may also be reduced by the use of tapered grooves, instead of the holes as shown.
  • the invention has been described as an ⁇ improved lens for radio frequency waves.
  • the refiections are reduced by applying a coating to the lens surface, or by skeletonizing the surface layer.
  • the undesired reflections may also be reduced by tapering the eifective surfaces of the lens, i. e., by tapering the surfaces which reiiect the radio wavesinto the medium from which the waves have come.
  • An ultra high frequency device consisting of an electric lens of a wave refracting material and l a reflection reducing surface disposed on at least one effective surface of said lens.
  • An ultra high frequency device consisting of an electric lens of a wave refracting material having substantially parallel sides and a reneetion reducing surface disposed on at least one effective surface of said lens.
  • An ultra high frequency device consisting of an electric lens of a Wave refracting material and a reiiection reducing coating disposed on at least one eiective surface of said lens.
  • An ultra high frequency device consisting of an electric lens of a wave refracting material having substantially parallel sides and a reliection reducing coating disposed on at least one effective surface of said lens.
  • An ultra high frequency device consisting of an electric lens of a wave refracting material and a surface having an effective thickness of an odd number of quarter wave lengths of said waves. disposed on at least one wave impinging surface of said lens whereby the reflection of said waves from said surfaces is reduced.
  • An ultra high frequency device consisting of an electric lens of a wave refracting material and a coating having an effective thickness of an odd number of quarter wave lengths of said waves in said coating, disposed on at least one wave impinging surface of s aid lens whereby the reection of said waves from said surfaces is reduced.
  • An ultra high frequency device consisting of an electric lens of a wave refracting material having at least one curved surface and a skeletonized layer disposed on said curved surface and having an eifective thickness of an odd integral number of quarter wave lengths of the applied electric waves whereby the reection of said waves from said surface is reduced.
  • An ultra high frequency wave focusing device consisting of an electric lens of a wave refracting material having substantially parallel sides and at least one curved surface and a pair of conductive elements disposed parallel to each other, parallel to said surfaces and extending beyond said lens and away from said curved surface.
  • a device of the character of claim 8 in which the pairs of conductive elements are curved in the region extending away from said curved surface.
  • An ultra high frequency device consisting of an electric lens of a wave refracting material having at least one curved surface and having parallel sides and means for reducing the index of refraction of the material on said curved surface and having an effective thickness of an odd number of quarter wave lengths of the applied electric waves whereby the reflection of said Waves from said surface is reduced.
  • An ultra high frequency wave focusing device consisting of an electric lens of a wave refracting material having substantially parallel sides and at least one curved surface and a pair of conductive elements disposed-parallel to each other, parallel to said surfaces and extending beyond said lens in at least one direction.
  • An ultra high frequency wave refracting device consisting of wave refracting material having substantially parallel sides ve or more wave lengths long perpendicular to the direction of motion of the wavefront placed between parallel conducting sheets separated by 7i/2 or less.
  • An ultra high frequency device consisting of on electric lens of a wave refracting material and a reiiection reducing surface, saidsurface including at least one projecting portion tapering along the axis of the lens.
  • radio wave device consisting of a mate-

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US532381A 1944-04-22 1944-04-22 Lens for radio-frequency waves Expired - Lifetime US2415352A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BE474864D BE474864A (de) 1944-04-22
US532381A US2415352A (en) 1944-04-22 1944-04-22 Lens for radio-frequency waves
GB10213/45A GB608949A (en) 1944-04-22 1945-04-23 Lens for ultra-high frequency electric waves

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US532381A US2415352A (en) 1944-04-22 1944-04-22 Lens for radio-frequency waves

Publications (1)

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US2415352A true US2415352A (en) 1947-02-04

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US (1) US2415352A (de)
BE (1) BE474864A (de)
GB (1) GB608949A (de)

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2524292A (en) * 1944-04-18 1950-10-03 Rca Corp Radio vision system with high-speed scanner for short radio waves
US2530826A (en) * 1948-02-03 1950-11-21 Bell Telephone Labor Inc Radio relay system
US2547416A (en) * 1946-12-19 1951-04-03 Bell Telephone Labor Inc Dielectric lens
US2549721A (en) * 1944-05-16 1951-04-17 Henry A Straus Antenna system of variable directivity and high resolution
US2561077A (en) * 1946-04-04 1951-07-17 Honeywell Regulator Co Radiation pyrometer
US2562277A (en) * 1946-04-08 1951-07-31 Bell Telephone Labor Inc Metallic lens directive antenna system
US2571612A (en) * 1948-02-24 1951-10-16 Robert H Rines Stereoscopic image reception by millimetric radiation
US2576181A (en) * 1947-10-28 1951-11-27 Rca Corp Focusing device for centimeter waves
US2577463A (en) * 1944-05-17 1951-12-04 Rca Corp Device for transmission and reception of very short electrical waves
US2579324A (en) * 1947-05-16 1951-12-18 Bell Telephone Labor Inc Metallic structure for delaying propagated waves
US2585562A (en) * 1947-12-04 1952-02-12 Bell Telephone Labor Inc Directive antenna system
US2617934A (en) * 1945-05-02 1952-11-11 Edward B Mcmillan Antenna housing
US2636125A (en) * 1948-04-10 1953-04-21 Bell Telephone Labor Inc Selective electromagnetic wave system
DE894421C (de) * 1948-10-03 1953-10-26 Siemens Ag Anordnung zur diathermischen Bestrahlung
US2669657A (en) * 1949-11-19 1954-02-16 Bell Telephone Labor Inc Electromagnetic lens
US2698901A (en) * 1948-03-17 1955-01-04 Wilkes Gilbert Back-radiation reflector for microwave antenna systems
US2716190A (en) * 1951-02-23 1955-08-23 Dow Chemical Co Dielectric material
US2747184A (en) * 1950-06-23 1956-05-22 Bell Telephone Labor Inc Wave refracting devices
US2822542A (en) * 1954-10-18 1958-02-04 Motorola Inc Directive antenna
US2959783A (en) * 1948-03-16 1960-11-08 Iams Harley Scanning antennas using dielectric with variable refraction
US3101472A (en) * 1958-11-21 1963-08-20 Beam Guidance Inc Transmission of electromagnetic wave beams
US3122742A (en) * 1957-11-22 1964-02-25 Diamond Antenna & Microwave Co Radio frequency to light frequency transducer
US3359560A (en) * 1962-08-17 1967-12-19 Armstrong Cork Co Cylindrical dielectric lens
US3441784A (en) * 1967-04-26 1969-04-29 Varian Associates Ridged dielectric window with titanium suboxide solely on ridges
US3550139A (en) * 1968-07-05 1970-12-22 North American Rockwell Hemispherical dielectric lens type antenna employing a uniform dielectric
US4181774A (en) * 1978-12-19 1980-01-01 The United States Of America As Represented By The Secretary Of The Air Force Electromagnetic interference filter window
US4556070A (en) * 1983-10-31 1985-12-03 Varian Associates, Inc. Hyperthermia applicator for treatment with microwave energy and ultrasonic wave energy
WO1986005327A1 (en) * 1985-02-28 1986-09-12 Stiftelsen For Industriell Og Teknisk Forskning Ve Hybrid mode horn antennas
US5017939A (en) * 1989-09-26 1991-05-21 Hughes Aircraft Company Two layer matching dielectrics for radomes and lenses for wide angles of incidence
US20070268198A1 (en) * 2006-05-17 2007-11-22 Marshall Dean R Refractive compact range
US20160006129A1 (en) * 2014-07-07 2016-01-07 Google Inc. Horn Lens Antenna
US10950951B2 (en) * 2018-03-23 2021-03-16 Mitsubishi Electric Corporation Radar device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3151324A (en) * 1957-03-18 1964-09-29 Mcmillan Corp Of North Carolin Wide-band electromagneticradiation absorber

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2085406A (en) * 1933-08-31 1937-06-29 Rca Corp Electrical device
US2240157A (en) * 1938-05-25 1941-04-29 American Optical Corp Ophthalmic lens
US2273447A (en) * 1939-09-07 1942-02-17 Bell Telephone Labor Inc Unidirective energy radiating system
US2331716A (en) * 1940-09-26 1943-10-12 Eastman Kodak Co Nonreflecting coating
US2361589A (en) * 1940-08-14 1944-10-31 American Optical Corp Lens

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2085406A (en) * 1933-08-31 1937-06-29 Rca Corp Electrical device
US2240157A (en) * 1938-05-25 1941-04-29 American Optical Corp Ophthalmic lens
US2273447A (en) * 1939-09-07 1942-02-17 Bell Telephone Labor Inc Unidirective energy radiating system
US2361589A (en) * 1940-08-14 1944-10-31 American Optical Corp Lens
US2331716A (en) * 1940-09-26 1943-10-12 Eastman Kodak Co Nonreflecting coating

Cited By (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2524292A (en) * 1944-04-18 1950-10-03 Rca Corp Radio vision system with high-speed scanner for short radio waves
US2549721A (en) * 1944-05-16 1951-04-17 Henry A Straus Antenna system of variable directivity and high resolution
US2577463A (en) * 1944-05-17 1951-12-04 Rca Corp Device for transmission and reception of very short electrical waves
US2617934A (en) * 1945-05-02 1952-11-11 Edward B Mcmillan Antenna housing
US2561077A (en) * 1946-04-04 1951-07-17 Honeywell Regulator Co Radiation pyrometer
US2562277A (en) * 1946-04-08 1951-07-31 Bell Telephone Labor Inc Metallic lens directive antenna system
US2547416A (en) * 1946-12-19 1951-04-03 Bell Telephone Labor Inc Dielectric lens
US2579324A (en) * 1947-05-16 1951-12-18 Bell Telephone Labor Inc Metallic structure for delaying propagated waves
US2576181A (en) * 1947-10-28 1951-11-27 Rca Corp Focusing device for centimeter waves
US2585562A (en) * 1947-12-04 1952-02-12 Bell Telephone Labor Inc Directive antenna system
US2530826A (en) * 1948-02-03 1950-11-21 Bell Telephone Labor Inc Radio relay system
US2571612A (en) * 1948-02-24 1951-10-16 Robert H Rines Stereoscopic image reception by millimetric radiation
US2959783A (en) * 1948-03-16 1960-11-08 Iams Harley Scanning antennas using dielectric with variable refraction
US2698901A (en) * 1948-03-17 1955-01-04 Wilkes Gilbert Back-radiation reflector for microwave antenna systems
US2636125A (en) * 1948-04-10 1953-04-21 Bell Telephone Labor Inc Selective electromagnetic wave system
DE894421C (de) * 1948-10-03 1953-10-26 Siemens Ag Anordnung zur diathermischen Bestrahlung
US2669657A (en) * 1949-11-19 1954-02-16 Bell Telephone Labor Inc Electromagnetic lens
US2747184A (en) * 1950-06-23 1956-05-22 Bell Telephone Labor Inc Wave refracting devices
US2716190A (en) * 1951-02-23 1955-08-23 Dow Chemical Co Dielectric material
US2822542A (en) * 1954-10-18 1958-02-04 Motorola Inc Directive antenna
US3122742A (en) * 1957-11-22 1964-02-25 Diamond Antenna & Microwave Co Radio frequency to light frequency transducer
US3101472A (en) * 1958-11-21 1963-08-20 Beam Guidance Inc Transmission of electromagnetic wave beams
US3359560A (en) * 1962-08-17 1967-12-19 Armstrong Cork Co Cylindrical dielectric lens
US3441784A (en) * 1967-04-26 1969-04-29 Varian Associates Ridged dielectric window with titanium suboxide solely on ridges
US3550139A (en) * 1968-07-05 1970-12-22 North American Rockwell Hemispherical dielectric lens type antenna employing a uniform dielectric
US4181774A (en) * 1978-12-19 1980-01-01 The United States Of America As Represented By The Secretary Of The Air Force Electromagnetic interference filter window
US4556070A (en) * 1983-10-31 1985-12-03 Varian Associates, Inc. Hyperthermia applicator for treatment with microwave energy and ultrasonic wave energy
WO1986005327A1 (en) * 1985-02-28 1986-09-12 Stiftelsen For Industriell Og Teknisk Forskning Ve Hybrid mode horn antennas
US4783665A (en) * 1985-02-28 1988-11-08 Erik Lier Hybrid mode horn antennas
US5017939A (en) * 1989-09-26 1991-05-21 Hughes Aircraft Company Two layer matching dielectrics for radomes and lenses for wide angles of incidence
US20070268198A1 (en) * 2006-05-17 2007-11-22 Marshall Dean R Refractive compact range
US7541994B2 (en) * 2006-05-17 2009-06-02 Raytheon Company Refractive compact range
US20160006129A1 (en) * 2014-07-07 2016-01-07 Google Inc. Horn Lens Antenna
US9722316B2 (en) * 2014-07-07 2017-08-01 Google Inc. Horn lens antenna
US10950951B2 (en) * 2018-03-23 2021-03-16 Mitsubishi Electric Corporation Radar device

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Publication number Publication date
BE474864A (de)
GB608949A (en) 1948-09-23

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