US3688311A - Parabolic antennas - Google Patents

Parabolic antennas Download PDF

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Publication number
US3688311A
US3688311A US391076A US3688311DA US3688311A US 3688311 A US3688311 A US 3688311A US 391076 A US391076 A US 391076A US 3688311D A US3688311D A US 3688311DA US 3688311 A US3688311 A US 3688311A
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United States
Prior art keywords
reflector
focus
originating
source
offset
Prior art date
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Expired - Lifetime
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US391076A
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English (en)
Inventor
Jacques Salmon
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Thales SA
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CSF Compagnie Generale de Telegraphie sans Fil SA
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/42—Housings not intimately mechanically associated with radiating elements, e.g. radome
    • H01Q1/421—Means for correcting aberrations introduced by a radome
    • 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
    • H01Q15/12—Refracting or diffracting devices, e.g. lens, prism functioning also as polarisation filter
    • 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
    • H01Q15/14—Reflecting surfaces; Equivalent structures
    • H01Q15/22—Reflecting surfaces; Equivalent structures functioning also as polarisation filter
    • 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

Definitions

  • ABSTRACT An ultra high frequency antenna comprising a reflecn fio p Dan tor having a focus and a focal plane, one radiating [30] Foreign App ca n ty source at said focus and at least one radiating source Sept. 9, France in said Plane ofiset respe t to f for illuminating said reflector, said sources producing 56, 343/78 at least two wave fronts of different directions and 343/840 phase correcting means in the path of the wave [51] Int. Cl.
  • Antennas of this kind generally comprise several horns situated in the focal plane of a reflector, which is generally parabolic.
  • Waves radiated by each horn are transformed, after reflection on the reflector, into waves which are plane, as a first approximation. This is strictly true in the case of a horn placed at the focus of the paraboloid. But the farther the horn is placed from the focus, the less plane are the wave surfaces.
  • an antenna comprising a correcting arrangement for rendering plane the equiphase surfaces of the waves issued from the horns which are not positioned at the reflector focus, this arrangement being placed on the path of these waves and away from the waves issuing from the horn positioned at the reflector focus.
  • FIGS. 1 and 2 show, very diagrammatically, two embodiments of the antenna according to the invention.
  • FIGS. 3 and 4 show in plane view two details of FIG. 1.
  • the antenna shown in FIG. 1 comprises two horns: a horn S is placed at the focus of a parabolic reflector A and a further horn S is placed at a distance from horn S in the focal plane of reflector A. Both horns transmit vertic ally/potflized waves.
  • Reflector A is built up, as-
  • FIG. 3 which are spaced apart by a distance of the order Al I 0, Abeing the operating wavelength.
  • the arrow in FIG. 3 indicates the direction of the electric field of the wave radiated by horns S, and 8-,.
  • a further reflector M formed by wires inclined by 45 to the horizontal, is positioned for receiving the waves reflected by reflector A. It is followed by reflector E, having a full reflecting surface and spaced by M4 from reflector M. Reflectors M and E are positioned normally to the axis of reflector A. Reflector M is shown in FIG. 4.
  • the waves transmitted by horn S are vertically polarized. These waves are reflected as plane waves R by reflector A.
  • the vertically polarized wave R may be considered as the resultant of two component plane waves respectively polarized norma lly and parallel to the wires of reflector M.
  • Vectors @(L represent respectively the electric fields of wave R and of said two components.
  • the plane wave parallel to the wires is reflected by the latter with phase inversion, as indicated by vector in opposition to vector while the wave normal to the wires propagates through reflector M and is reflected by reflector E with a phase inversion. Due to the fact that the distance B between reflectors M and E is )t/4 the electric field vector e',, at the wires, of the wave reflected by reflector E, is again parallel to E].
  • the two reflected component waves combine to form a wave whose electric field is the resultant Mctgrs e',, i.e., 2?, and P i.e. along the horizontal
  • the waves radiated by horn 8 except for the fact that they do not possess, after reflection upon mirror A, plane equiphase surfaces, horn S being offset with respect to the forms of reflector A.
  • this equiphase surface P is shown in FIG. 1.
  • reflector M is curved in its upper part C turning its concavity in the same sense as surface P, so compensating phase adva'nces.
  • the shape of the equiphase surface is as shown at P It will be noted that the only equiphase surfaces to be corrected are those of the waves from horns which are substantially offset with respect to the focus of reflector A.
  • Sources which are more offset than in conventional systems may be used in combination with a source at the focus, which results in respective plane waves having direction of propagation at large angles with respect to each other; thus the average space angle covered by the whole radiation system, or radiation aperture, may be 10 times, for example, the space angle covered by the radiation originating from a single source.
  • the curvature of mirror M is calculated for the horn which is most offset with respect to the focus. The more offset the intermediate sources, the more they are subject to correction.
  • the shape of the curved part can be easily improved by trail and error.
  • FIG. 2 shows another embodiment of the invention.
  • the primary sources S are placed in the focal plane of a parabolic reflector A.
  • the whole assembly is placed in a radome Ra.
  • the correction device C is a lens placed at the top of the radome, and through which propagate the waves radiated by the sources which are offset with respect to the focus of reflector A.
  • this lens may be constituted by a zone, at the top of the radome, of a thickness which is variable and greater than the normal thickness of the radome, this thickness not exceeding one wavelength of the radiated wave.
  • An ultra high frequency antenna comprising a reflector having a focus and a focal plane, one radiating source at said focus and at least one radiating source in said focal plane, offset with respect to said focus, for illuminating said reflector, said sources producing at least two wave fronts of different directions and phase correcting means in the path of the wave front(s) originating from said offset source(s), said correcting means lying outside the path of said wave front originating from said source located at said focus.
  • phase correcting means comprise a lens located in the path of the waves radiated by said offset source(s).
  • phase correcting means comprise a second reflector having a planar portion for reflecting wave front originating from said source located at said focus upon reflection thereof on said first mentioned reflector and at least a curved end portion for reflecting wave front(s) originating from said offset source(s) upon reflection thereof on said first mentioned reflector.
  • An antenna as claimed in claim 1, comprising a plurality of offset sources in said focal plane, said cor recting meanslying in the path of the wave fronts originating from said plurality of sources.
  • said sources radiate waves polarized in a first direction
  • said phase correcting means comprise a second reflector having a planar portion for reflecting the wave front originating from said source located at said focus, upon reflection thereof on said first mentioned reflector, and curved end portions for reflecting the wave fronts originating from said plurality of offset sources upon reflection thereof on said first mentioned reflector
  • said first reflector comprises wires parallel to said first direction
  • said second reflector comprises parallel wires inclined at 45 to said first direction
  • a screen being disposed behind said second reflector, parallel thereto, at a distance equal to M4, A being the operating wavelength.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Aerials With Secondary Devices (AREA)
US391076A 1963-09-09 1964-08-19 Parabolic antennas Expired - Lifetime US3688311A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR946916 1963-09-09

Publications (1)

Publication Number Publication Date
US3688311A true US3688311A (en) 1972-08-29

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ID=8811967

Family Applications (1)

Application Number Title Priority Date Filing Date
US391076A Expired - Lifetime US3688311A (en) 1963-09-09 1964-08-19 Parabolic antennas

Country Status (5)

Country Link
US (1) US3688311A (nl)
DE (1) DE1441642C3 (nl)
FR (1) FR1604514A (nl)
GB (1) GB1268341A (nl)
NL (1) NL138904B (nl)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4145695A (en) * 1977-03-01 1979-03-20 Bell Telephone Laboratories, Incorporated Launcher reflectors for correcting for astigmatism in off-axis fed reflector antennas
US4339757A (en) * 1980-11-24 1982-07-13 Bell Telephone Laboratories, Incorporated Broadband astigmatic feed arrangement for an antenna
US4343004A (en) * 1980-11-24 1982-08-03 Bell Telephone Laboratories, Incorporated Broadband astigmatic feed arrangement for an antenna
US4491848A (en) * 1982-08-30 1985-01-01 At&T Bell Laboratories Substantially frequency-independent aberration correcting antenna arrangement
US4535338A (en) * 1982-05-10 1985-08-13 At&T Bell Laboratories Multibeam antenna arrangement
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
US4755826A (en) * 1983-01-10 1988-07-05 The United States Of America As Represented By The Secretary Of The Navy Bicollimated offset Gregorian dual reflector antenna system
US4769646A (en) * 1984-02-27 1988-09-06 United Technologies Corporation Antenna system and dual-fed lenses producing characteristically different beams
US4791427A (en) * 1985-11-22 1988-12-13 United Technologies Corporation Multimode, multispectral antenna
US6225961B1 (en) 1999-07-27 2001-05-01 Prc Inc. Beam waveguide antenna with independently steerable antenna beams and method of compensating for planetary aberration in antenna beam tracking of spacecraft

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2264006B (en) * 1992-02-01 1995-09-27 British Aerospace Space And Co A reflector antenna assembly for dual linear polarisation

Citations (4)

* 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
US2790169A (en) * 1949-04-18 1957-04-23 Itt Antenna
US2846680A (en) * 1946-06-29 1958-08-05 Bell Telephone Labor Inc Directive antennas
US2975419A (en) * 1959-10-13 1961-03-14 Newell H Brown Microwave antenna reflector system for scanning by displacement of focal image

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2846680A (en) * 1946-06-29 1958-08-05 Bell Telephone Labor Inc Directive antennas
US2790169A (en) * 1949-04-18 1957-04-23 Itt Antenna
US2736895A (en) * 1951-02-16 1956-02-28 Elliott Brothers London Ltd High frequency radio aerials
US2975419A (en) * 1959-10-13 1961-03-14 Newell H Brown Microwave antenna reflector system for scanning by displacement of focal image

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4145695A (en) * 1977-03-01 1979-03-20 Bell Telephone Laboratories, Incorporated Launcher reflectors for correcting for astigmatism in off-axis fed reflector antennas
US4339757A (en) * 1980-11-24 1982-07-13 Bell Telephone Laboratories, Incorporated Broadband astigmatic feed arrangement for an antenna
US4343004A (en) * 1980-11-24 1982-08-03 Bell Telephone Laboratories, Incorporated Broadband astigmatic feed arrangement for an antenna
US4535338A (en) * 1982-05-10 1985-08-13 At&T Bell Laboratories Multibeam antenna arrangement
US4491848A (en) * 1982-08-30 1985-01-01 At&T Bell Laboratories Substantially frequency-independent aberration correcting antenna arrangement
US4755826A (en) * 1983-01-10 1988-07-05 The United States Of America As Represented By The Secretary Of The Navy Bicollimated offset Gregorian dual reflector antenna system
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
US4769646A (en) * 1984-02-27 1988-09-06 United Technologies Corporation Antenna system and dual-fed lenses producing characteristically different beams
US4791427A (en) * 1985-11-22 1988-12-13 United Technologies Corporation Multimode, multispectral antenna
US6225961B1 (en) 1999-07-27 2001-05-01 Prc Inc. Beam waveguide antenna with independently steerable antenna beams and method of compensating for planetary aberration in antenna beam tracking of spacecraft
US6246378B1 (en) 1999-07-27 2001-06-12 Prc, Inc. Beam waveguide antenna with independently steerable antenna beams and method of compensating for planetary aberration in antenna beam tracking of spacecraft

Also Published As

Publication number Publication date
FR1604514A (nl) 1971-11-29
DE1441642C3 (de) 1979-08-30
NL6410250A (nl) 1972-03-27
GB1268341A (en) 1972-03-29
DE1441642A1 (de) 1972-07-27
NL138904B (nl) 1973-05-15
DE1441642B2 (de) 1974-03-28

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