US2829366A - Antenna feed - Google Patents

Antenna feed Download PDF

Info

Publication number
US2829366A
US2829366A US496742A US49674255A US2829366A US 2829366 A US2829366 A US 2829366A US 496742 A US496742 A US 496742A US 49674255 A US49674255 A US 49674255A US 2829366 A US2829366 A US 2829366A
Authority
US
United States
Prior art keywords
reflector
sleeve
aperture
wave guide
flat
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
US496742A
Inventor
David G Armstrong
Michelson Max
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.)
Raytheon Co
Original Assignee
Raytheon Manufacturing Co
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 Raytheon Manufacturing Co filed Critical Raytheon Manufacturing Co
Priority to US496742A priority Critical patent/US2829366A/en
Application granted granted Critical
Publication of US2829366A publication Critical patent/US2829366A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • H01Q19/12—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 wherein the surfaces are concave
    • H01Q19/13—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 wherein the surfaces are concave the primary radiating source being a single radiating element, e.g. a dipole, a slot, a waveguide termination
    • H01Q19/134—Rear-feeds; Splash plate feeds

Definitions

  • This application relates to a feed for a parabolic antenna, and more particularly to the type that propagates energy from the end of a wave guide against a flat reflector and back against a parabolic reflector.
  • this is accomplished by mounting a conductive sleeve coaxially about the end of the wave guide and separated from it.
  • a block of metal not in contact with the sleeve and formed with a matching groove.
  • the block is supported between two pieces of insulating material, one formed with a matching recess and placed at the aperture of the wave guide, and one separating the block from a metallic plate closing the end of the sleeve.
  • the metallic block is'so mounted and its matching groove is so dimensioned that it presents a non-contacting short at the operating frequency across the sleeve so that the propagated energy is reflected back and through the space between the guide and sleeve.
  • Fig. 1 is an isometric view of an antenna utilizing the invention
  • Fig. 2 is a longitudinal section of one embodiment of the feed of the invention
  • Fig. 3 is a section taken along the line 33 of Fig. 2;
  • Fig. 4 is a section taken along the line 4-4 of Fig. 2;
  • Fig. 5 is a section taken along the line 5-5 of Fig. 2.
  • the reference numeral designates the reflector of a microwave antenna shaped as a paraboloid having a centrally located opening within which is 0 mounted a section of wave guide 11 shown as circular, although it may also be rectangular.
  • This wave guide is mounted along the axis of the paraboloid reflector.
  • the wave guide terminates in a coaxial sleeve.
  • the wave guide 11 terminates in an aperture surrounded by a flange 13 that extends outwardly along the inner surface of a ring 14 of insulating material formed with a slot 15 at its outer periphery, which is dimensioned so as to give the most advantageous match between free space and the interior of the sleeve. Its dimensioning also affects the pattern of the propagated energy.
  • the ring 14 may extend back from the opening in the sleeve along the outside of the wave guide.
  • the wave guide 11 is filled with a solid insulating material 16, such as polystyrene, having a dielectric constant that permits the wave guide to propagate radio frequency energy with the same efliciency as a considerably larger wave guide so that the feed may be of the smallest possible dimensions and operate as nearly as possible as a point source.
  • the feed of this invention will operate in the manner shown without the and with dimensions that are easily adjusted for use with p ice dielectric filling for the wave guide, but not as efliciently I as with this filling.
  • the dielectric filling is formed with an enlargement 17 at its outer end that is of the same diameter as the inner diameter of the sleeve 12.
  • This I enlarged end is formed with a cylindrical recess 18 of a diameter and depth sufficient to make a good'match across the discontinuity between the dielectric filling and a conductive cylindrical piece 20 which is formed with a notch 21 about its periphery so dimensioned as to present a short circuit across the'sleeve 12 to radio frequency energy propagated from the wave guide 11 without actually touching the walls of the sleeve. It is held in this position by a neoprene rubber O ring 22 and a metal disc 23 of the same diameter as the inside diameter of the sleeve 12. This disc 23 is in turn held in position by I a snap ring 24 of metal that fits intoa notch 25 in the J inner wall of the sleeve 12;
  • a concave main reflector having an axis, a vertex, and a focus, said focus lying on said axis, a wave guide of circular cross section extending through the vertex of said reflector and along said axis, said guide having an end aperture, and a flat circular reflector located in the region of the focus facing said aperture and said main reflector, said flat reflector being larger in area than said aperture, a conductive sleeve mounted concentric with the axis of the wave guide and supporting the flat reflector without making conductive contact with said flat reflector, said flat reflector being formed with a peripheral notch so dimensioned as to present substantially a short circuit across said sleeve to radio frequency energy propagated in said guide.
  • a concave main reflector having an axis, a vertex, and a focus, said focus lying on said axis, a wave guide of circular cross section filled with a dielectric material extending through the vertex of said reflector and along said axis, said guide having an end aperture, and a flat circular reflector located in the region of said focus facing said aperture and said main reflector, said flat reflector being larger in area than said aperture, a conductive'sleeve mounted concentric with the axis of the wave guideand supporting the flat reflector without making conductive contact with said flat reflector, said flat reflector being formed with a peripheral notch so dimensioned as to present susbtantially a short circuit across said sleeve to radio frequency energy propagated in said guide.
  • a concave main reflector having an axis, a vertex, and a focus, said focus lying on said axis
  • Patented Apr. 1,. 1958 I said main reflector, said flat reflector being larger in area than said aperture, a conductive sleeve mounted concentric with the axis of the wave guide and supporting the flat reflectonwithoutzmaking,conductive contact with;
  • saidflat reflector said dielectric filling of. said wave guide extending; outward, from said aperture to make supporting contact with said sleeve, said flat, reflector being formed" with a peripheral, notch so dimensioned; as to: present substantially a short circuit across said. sleeve to radiofrequency energy propagated in said guide.
  • a concave main reflector having an axis, a vertex, and a. focus, said focus; lying, on said axis,
  • said guide having an end, aperture, and a flat reflector in the rcgionof. the. focus facingsaid aperture and said main reflector, said flat reflector being larger in area than said aperture, a conductivelisleeve mounted; concentric with, the axis ofthe.
  • saidflatreflector being larger in area than said aperture, a conductive sleeve mounted concentric with the axis of the wave guide and supporting the flat reflector without making conductive contact with said flat reflector, said dielectric filling of said wave guide extending outward from said aperture to make supporting contact with said sleeve, said flat reflector being formed with a peripheral notch so dimensioned as to present substantially a short circuit across said sleeve to radio frequency energy propagated in said guide.
  • a wave guid'e having an end aperture, a flat reflector facing said aperture, sa'id flat reflector being larger in area than said aperture, and a conductive.
  • sleeve mounted concentric with the axis of the wave guide and supporting the flat reflector without making conductive contact with said flat reflector, said flat reflector being formed with a, peripheral notch so dimensionedas to present substantially a short circuit across. said sleeve to radio frequency energy propagated in said guide.
  • said flat circular reflector being larger in area than saidaperture, and a conductive sleeve mounted concentric with the axis of the wave guide and supportingttheiflat' reflector without making conductive contact withlsaidi flat reflector, said dielectric filling of said wave guideextending outward from said aperture to make supporting contact with said sleeve, said flat reflector being formed: with a peripheral notch so dimensioned as to present substantially a short circuit across said sleeve toradio frequency energy propagated in said guide.

Landscapes

  • Aerials With Secondary Devices (AREA)

Description

2,829,366 H ANTENNA FEED David G, Armstrong, West Newton, and Max Michelson, Newton, Mass., assignors to Raytheon Manufacturing Company, Waltham, Mass, a corporation of Delaware Application March 25, 1955, Serial No. 496,742
7 Claims. (Cl. 343-781) This application relates to a feed for a parabolic antenna, and more particularly to the type that propagates energy from the end of a wave guide against a flat reflector and back against a parabolic reflector.
In this type of antenna it is desirable to have the feed as close to a point source as possible. There is also a problem of impedance matching.
In the present invention this is accomplished by mounting a conductive sleeve coaxially about the end of the wave guide and separated from it. Within the sleeve is mounted a block of metal not in contact with the sleeve and formed with a matching groove. The block is supported between two pieces of insulating material, one formed with a matching recess and placed at the aperture of the wave guide, and one separating the block from a metallic plate closing the end of the sleeve. The metallic block is'so mounted and its matching groove is so dimensioned that it presents a non-contacting short at the operating frequency across the sleeve so that the propagated energy is reflected back and through the space between the guide and sleeve.
Other and further advantages of this invention will be apparent as the description thereof progresses, reference being bad to the accompanying drawing wherein:
Fig. 1 is an isometric view of an antenna utilizing the invention;
Fig. 2 is a longitudinal section of one embodiment of the feed of the invention;
Fig. 3 is a section taken along the line 33 of Fig. 2;
Fig. 4 is a section taken along the line 4-4 of Fig. 2; and
Fig. 5 is a section taken along the line 5-5 of Fig. 2.
In Fig.1 the reference numeral designates the reflector of a microwave antenna shaped as a paraboloid having a centrally located opening within which is 0 mounted a section of wave guide 11 shown as circular, although it may also be rectangular. This wave guide is mounted along the axis of the paraboloid reflector. The wave guide terminates in a coaxial sleeve.
The details of this sleeve are best shown in Figs. 2, 3, 4
and 5. The wave guide 11 terminates in an aperture surrounded by a flange 13 that extends outwardly along the inner surface of a ring 14 of insulating material formed with a slot 15 at its outer periphery, which is dimensioned so as to give the most advantageous match between free space and the interior of the sleeve. Its dimensioning also affects the pattern of the propagated energy. For this purpose the ring 14 may extend back from the opening in the sleeve along the outside of the wave guide. The wave guide 11 is filled with a solid insulating material 16, such as polystyrene, having a dielectric constant that permits the wave guide to propagate radio frequency energy with the same efliciency as a considerably larger wave guide so that the feed may be of the smallest possible dimensions and operate as nearly as possible as a point source. The feed of this invention will operate in the manner shown without the and with dimensions that are easily adjusted for use with p ice dielectric filling for the wave guide, but not as efliciently I as with this filling. The dielectric filling is formed with an enlargement 17 at its outer end that is of the same diameter as the inner diameter of the sleeve 12. This I enlarged end is formed with a cylindrical recess 18 of a diameter and depth sufficient to make a good'match across the discontinuity between the dielectric filling and a conductive cylindrical piece 20 Which is formed with a notch 21 about its periphery so dimensioned as to present a short circuit across the'sleeve 12 to radio frequency energy propagated from the wave guide 11 without actually touching the walls of the sleeve. It is held in this position by a neoprene rubber O ring 22 and a metal disc 23 of the same diameter as the inside diameter of the sleeve 12. This disc 23 is in turn held in position by I a snap ring 24 of metal that fits intoa notch 25 in the J inner wall of the sleeve 12;
Energy propagated down the guide 11 is reflected back I from the metal cylinder 20 through the opening between the guide and the sleeve 12 in the region occupied by the dielectric ring 14 which is transparent to radio frequency energy and strikes the paraboloid reflector 10, and is again reflected out into free space in the desired pattern. The resulting structure produces a feed for the paraboloid antenna that is weather proof, relatively easy to construct, easy to disassemble for cleaning and adjusting,
difierent design parameters.
of construction, materials and processes described, as many equivalents will suggest themselves to those skilled in the art. It is accordingly desired that the appended claims be given a broad interpretation commensurate with the scope of the invention within the art.
What is claimed is:
1. In combination, a concave main reflector having an axis, a vertex, and a focus, said focus lying on said axis, a wave guide of circular cross section extending through the vertex of said reflector and along said axis, said guide having an end aperture, and a flat circular reflector located in the region of the focus facing said aperture and said main reflector, said flat reflector being larger in area than said aperture, a conductive sleeve mounted concentric with the axis of the wave guide and supporting the flat reflector without making conductive contact with said flat reflector, said flat reflector being formed with a peripheral notch so dimensioned as to present substantially a short circuit across said sleeve to radio frequency energy propagated in said guide.
2. In combination, a concave main reflector having an axis, a vertex, and a focus, said focus lying on said axis, a wave guide of circular cross section filled with a dielectric material extending through the vertex of said reflector and along said axis, said guide having an end aperture, and a flat circular reflector located in the region of said focus facing said aperture and said main reflector, said flat reflector being larger in area than said aperture, a conductive'sleeve mounted concentric with the axis of the wave guideand supporting the flat reflector without making conductive contact with said flat reflector, said flat reflector being formed with a peripheral notch so dimensioned as to present susbtantially a short circuit across said sleeve to radio frequency energy propagated in said guide.
3. In combination, a concave main reflector having an axis, a vertex, and a focus, said focus lying on said axis,
Patented Apr. 1,. 1958 I said main reflector, said flat reflector being larger in area than said aperture, a conductive sleeve mounted concentric with the axis of the wave guide and supporting the flat reflectonwithoutzmaking,conductive contact with;
saidflat reflector, said dielectric filling of. said wave guide extending; outward, from said aperture to make supporting contact with said sleeve, said flat, reflector being formed" with a peripheral, notch so dimensioned; as to: present substantially a short circuit across said. sleeve to radiofrequency energy propagated in said guide.
4. In combination, a concave main reflector having an axis, a vertex, and a. focus, said focus; lying, on said axis,
a wave guide filled with a dielectric materialiextending;
through the. vertex of saidreflector andnalong; said axis,
said guide having an end, aperture, and a flat reflector in the rcgionof. the. focus facingsaid aperture and said main reflector, said flat reflector being larger in area than said aperture, a conductivelisleeve mounted; concentric with, the axis ofthe. wave guide andv supporting the flat re-- aperture and said main reflector, saidflatreflector being larger in area than said aperture, a conductive sleeve mounted concentric with the axis of the wave guide and supporting the flat reflector without making conductive contact with said flat reflector, said dielectric filling of said wave guide extending outward from said aperture to make supporting contact with said sleeve, said flat reflector being formed with a peripheral notch so dimensioned as to present substantially a short circuit across said sleeve to radio frequency energy propagated in said guide.
6. In combination, a wave guid'ehaving an end aperture, a flat reflector facing said aperture, sa'id flat reflector being larger in area than said aperture, and a conductive. sleeve mounted concentric with the axis of the wave guide and supporting the flat reflector without making conductive contact with said flat reflector, said flat reflector being formed with a, peripheral notch so dimensionedas to present substantially a short circuit across. said sleeve to radio frequency energy propagated in said guide.
7. in combination, a Wave guide of circular cross section filled with a dielectric material having an end aperture formed'witha flange, a flat reflector facingisaid aperture,
said flat circular reflector being larger in area than saidaperture, and a conductive sleeve mounted concentric with the axis of the wave guide and supportingttheiflat' reflector without making conductive contact withlsaidi flat reflector, said dielectric filling of said wave guideextending outward from said aperture to make supporting contact with said sleeve, said flat reflector being formed: with a peripheral notch so dimensioned as to present substantially a short circuit across said sleeve toradio frequency energy propagated in said guide.
References Cited in the file of this patent UNITED STATES 'PATENTS Cutler Sept. 20, 1949 I Cutler June 17,1941
US496742A 1955-03-25 1955-03-25 Antenna feed Expired - Lifetime US2829366A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US496742A US2829366A (en) 1955-03-25 1955-03-25 Antenna feed

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US496742A US2829366A (en) 1955-03-25 1955-03-25 Antenna feed

Publications (1)

Publication Number Publication Date
US2829366A true US2829366A (en) 1958-04-01

Family

ID=23973932

Family Applications (1)

Application Number Title Priority Date Filing Date
US496742A Expired - Lifetime US2829366A (en) 1955-03-25 1955-03-25 Antenna feed

Country Status (1)

Country Link
US (1) US2829366A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4058812A (en) * 1976-05-03 1977-11-15 Aradar Corporation Dish antenna with impedance matched splash plate feed
US4527166A (en) * 1981-03-26 1985-07-02 Luly Robert A Lightweight folding parabolic reflector and antenna system
US4608571A (en) * 1981-03-26 1986-08-26 Luly Robert A Collapsible parabolic reflector
US4963878A (en) * 1986-06-03 1990-10-16 Kildal Per Simon Reflector antenna with a self-supported feed
US5889497A (en) * 1994-05-20 1999-03-30 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Ultrawideband transverse electromagnetic mode horn transmitter and antenna
US5959590A (en) * 1996-08-08 1999-09-28 Endgate Corporation Low sidelobe reflector antenna system employing a corrugated subreflector
US20110081192A1 (en) * 2009-10-02 2011-04-07 Andrew Llc Cone to Boom Interconnection

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2422184A (en) * 1944-01-15 1947-06-17 Bell Telephone Labor Inc Directional microwave antenna
US2482158A (en) * 1945-07-21 1949-09-20 Bell Telephone Labor Inc Directive antenna system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2422184A (en) * 1944-01-15 1947-06-17 Bell Telephone Labor Inc Directional microwave antenna
US2482158A (en) * 1945-07-21 1949-09-20 Bell Telephone Labor Inc Directive antenna system

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4058812A (en) * 1976-05-03 1977-11-15 Aradar Corporation Dish antenna with impedance matched splash plate feed
US4527166A (en) * 1981-03-26 1985-07-02 Luly Robert A Lightweight folding parabolic reflector and antenna system
US4608571A (en) * 1981-03-26 1986-08-26 Luly Robert A Collapsible parabolic reflector
US4963878A (en) * 1986-06-03 1990-10-16 Kildal Per Simon Reflector antenna with a self-supported feed
US5889497A (en) * 1994-05-20 1999-03-30 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Ultrawideband transverse electromagnetic mode horn transmitter and antenna
US5959590A (en) * 1996-08-08 1999-09-28 Endgate Corporation Low sidelobe reflector antenna system employing a corrugated subreflector
US20110081192A1 (en) * 2009-10-02 2011-04-07 Andrew Llc Cone to Boom Interconnection

Similar Documents

Publication Publication Date Title
US2588610A (en) Directional antenna system
US2677055A (en) Multiple-lobe antenna assembly
US2433924A (en) Antenna
US2829366A (en) Antenna feed
US3119109A (en) Polarization filter antenna utilizing reflector consisting of parallel separated metal strips mounted on low loss dish
SE515493C2 (en) Sub reflector, feeder and reflector antenna including such a sub reflector.
US2531454A (en) Directive antenna structure
US2705776A (en) Switches for high frequency waves
US2600278A (en) Variable capacity cavity tuning
US2747137A (en) High frequency electrical apparatus
US2881431A (en) Ring source omnidirectional antenna
US2435804A (en) Cavity resonator magnetron device
US2782383A (en) Cavity resonator
US3086205A (en) Ring scanning antenna adapted for flush mounting
GB600327A (en) Improvement in directive antennae
US2466060A (en) Electron discharge device
US2556969A (en) Antenna reflector
US2656464A (en) Feed locus for semiparabolic reflector
US2870441A (en) Microwave antennas
US2605419A (en) Wave guide feed for illuminating parabolic reflectors
US2656484A (en) Tunable cavity
US3002164A (en) High frequency transmission line coupling device
US2878415A (en) Electron discharge device
US3414760A (en) A frequency diversity coaxial magnetron
US2817086A (en) Elliptically polarized antennas