US2370053A - Directive antenna system - Google Patents

Directive antenna system Download PDF

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Publication number
US2370053A
US2370053A US372609A US37260940A US2370053A US 2370053 A US2370053 A US 2370053A US 372609 A US372609 A US 372609A US 37260940 A US37260940 A US 37260940A US 2370053 A US2370053 A US 2370053A
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United States
Prior art keywords
reflector
radiator
cone
antenna system
radiating
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Expired - Lifetime
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US372609A
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Nils E Lindenblad
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RCA Corp
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RCA Corp
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    • 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

  • the present invention relates to an antenna system for ultra-high frequency radiation and, more particularly, to antenna systems employing parabolic reflectors. for projection of the radiation in a desired direction.
  • I also propose to improve the fleld distribution across the reflector by placing a conductive cone between the radiator within the reflector and the portion of the reflector immediately back of the radiator.
  • reference character i indicates a parabolic reflector having mounted therein at the focus a radiating antenna structure 2.
  • a portion of the reflector i is shown broken away in order that the interior arrangement may be clearly seen.
  • the antenna structure 2 is connected to energizing or signal transducer means (not shown) by a transmission line TL.
  • a conductive disc or shading element 3 which preferably has a diameter of the order of one wavelength and is placed a distance of a half the operating wavelength or less in front of radiator 2.
  • the distance between the radiator 2 and the conductive disc 3 is not critical but in general it will be somewhat less than a half of the operating wavelength.
  • the presence of the disc-like shading element 3 prevents the direct radiation of energy from radiator 2 and thus improves the radiation pattern of the antenna ystem in the same way as do the spherical caps previously known in the art.
  • the flat conductive disc 3 does not change the resonance condition of the radiator to nearly the same extent as the spherical caps due to sectional variation of distance to radiator.
  • the distance from the radiator 2 to the reflecting surface of the reflector I increases considerably towards the edge of the reflector. I have discovered that this condition results in a poor field distribution across the face of the reflector so that all the gain that is theoretically possible to obtain with a certain reflector area is not obtained. I find that it is possible to correct this condition by the use of a centrally located cone 5, as indicated in the accompanying drawing. A portion of'reflector i has been shown as broken away in order to more clearly disclose cone 5. The presence of this cone does not materially affect the resonance condition of the radiator. As indicated in the drawing, the included angle of the cone 5 should preferably be of the order of and the length of the side should be of the order of a half wavelength, though this is not critical.
  • my invention is not element disposed across the opening of said reflector in front of said radiating means at a distance less than half the operating wavelength therefrom and means interposed between said reflector and said radiating means for re-distributing the field within said reflector for most effective use of the surface of said reflector.
  • An antenna system comprising radiating means within a parabolic reflector, a flat shading element disposed across the opening of said reflector in front of said radiator means at a distance less than half the operating wavelength therefrom and means interposed between said reflector and said radiating means for limiting the effective surface of said refle tor, said last means comprising a right circular cone.
  • An antenna system comprising radiating means within a parabolic reflector, a flat shading disc disposed across the opening of said reflector in front of said radiator means at a distance less than half the operating wavelength therefrom and means interposed between said reflector and said radiating means for limiting the effective surface of said reflector, said last means comprising a right circular cone having a side equal in length to a half of the operating wavelength.
  • An antenna system comprising radiating means within a parabolic reflector, a flat shading disc disposed across the opening of said reflector in front of said radiator means at a distance less than half the operating wavelength therefrom and means interposed between said reflector and said radiating means for re-distributing the fleld within said reflector for most effective use of the surface of said reflector, said last m ans comprising a right circular cone having a side equal in length to a half of the operating wavelength.
  • An antenna system comprising radiating means within a parabolic reflector and means interposed between said reflector and said radiating means for distributing the fleld within said reflector for a most effective use of the surface of said reflector, said means comprising a conductive cone, the apex of said cone facing said radiating means, said cone having a side length of the order of one-half of the operating wavelength of said system.
  • An antenna system comprising electromagnetic radiating means within a parabolic reflector and means interposed between said radiating means and a portion of said reflector for limiting the distribution of radiated energy to predetermined portions of said reflector, said means comprising a conductive body tapering from said reflector toward said radiating means, the length of the tapering side of said body being of the order of one-half of the operating wavelength of said system.
  • An antenna system comprising radiator means within a parabolic reflector and means interposed between said reflector and said radiator means for distributing the field within said reflector for a most effective use of the surface of said reflector, said means comprising a right circular conductive cone, the apex of said cone facing said radiator means, said cone having a side length of the order of one-half of the operating Wavelength of said system.
  • An ant nna system including radiating means within a parabolic reflector, a flat shading element disposed across the opening of said reflector in front of said radiating means, and means interposed between said reflector and said radiating means for re-distributing the fleld within said reflector for the most effective use of the surface of said reflector, said last-mentioned means including a conductive cone, the apex of said cone facing said radiating means.

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  • Aerials With Secondary Devices (AREA)

Description

20, 1945- N. E. LINDENBLAD 0,
DIRECTIVE ANTENNA SYSTEM Filed D60. 31, 1940 INVENTOR NILS 5. LINDENBLAD BY M'z/(A/ ATTORNEY Patented Feb. 20, 1945 DIRECTIVE ANTENNA SYSTEM Nils E. Llndenblad, Rocky Point, N.'Y., aslignor to Radio Corporation of America, a corporation of Delaware Application December 31, 1940, Serial No. 372,609
9 Claims.
The present invention relates to an antenna system for ultra-high frequency radiation and, more particularly, to antenna systems employing parabolic reflectors. for projection of the radiation in a desired direction.
It has previously been attempted to conserve the direct forward radiation from a radiator at the focus of a parabolic reflector by means of a spherical cap over the radiator. This method yields an improvement in directivity but also results in an increase in' the resonance characteristic or the Q of the radiation system. This is very seldom desirable in modern wide band frethe order of a wavelength in diameter or less at a distance less than a half wavelength in front of the radiator.
According to another aspect of my invention, I also propose to improve the fleld distribution across the reflector by placing a conductive cone between the radiator within the reflector and the portion of the reflector immediately back of the radiator. My invention will be more fully understood by reference to the following detailed description which is accompanied by a drawing in which reference character i indicates a parabolic reflector having mounted therein at the focus a radiating antenna structure 2. A portion of the reflector i is shown broken away in order that the interior arrangement may be clearly seen. The antenna structure 2 is connected to energizing or signal transducer means (not shown) by a transmission line TL. Immediately in front of the radiator 2 is placed a conductive disc or shading element 3 which preferably has a diameter of the order of one wavelength and is placed a distance of a half the operating wavelength or less in front of radiator 2. The distance between the radiator 2 and the conductive disc 3 is not critical but in general it will be somewhat less than a half of the operating wavelength. The presence of the disc-like shading element 3 prevents the direct radiation of energy from radiator 2 and thus improves the radiation pattern of the antenna ystem in the same way as do the spherical caps previously known in the art.
However, the flat conductive disc 3 does not change the resonance condition of the radiator to nearly the same extent as the spherical caps due to sectional variation of distance to radiator.
In a reflector of practical parameter, the distance from the radiator 2 to the reflecting surface of the reflector I increases considerably towards the edge of the reflector. I have discovered that this condition results in a poor field distribution across the face of the reflector so that all the gain that is theoretically possible to obtain with a certain reflector area is not obtained. I find that it is possible to correct this condition by the use of a centrally located cone 5, as indicated in the accompanying drawing. A portion of'reflector i has been shown as broken away in order to more clearly disclose cone 5. The presence of this cone does not materially affect the resonance condition of the radiator. As indicated in the drawing, the included angle of the cone 5 should preferably be of the order of and the length of the side should be of the order of a half wavelength, though this is not critical.
The theoretical formula for the gain of a reflector having an opening area A expressed in terms of the wavelength squared and when using uniform power distribution is Gain=K x A where K is equal to 7.8. Those skilled in the art have heretofore found that it is difflcult to exceed practically a value of 4 for the constant K as compared to the theoretical value of 7.8.
By utilizing the flat conductive disc 3 and the centrally located cone 5 in accordance with the teachings of my invention, it is possible to obtain a value for K of 5.6, or more, which represents a conservative interpretation of actual measurements on a physical embodiment of my invention. It will be seen that this is a substantial improvement over what has previously been obtainable. My invention has been described in detail with reference to a reflector in the form of a parab oloid of revolution and a conical angle limiting structure but it should be clearly understood that the same principles may be used with a reflector having the form of a cylindrical parabola and a prismatic angle limiting structure.
While I have particularly shown and describ d several modifications of my invention, it is to be distinctly understood that my invention is not element disposed across the opening of said reflector in front of said radiating means at a distance less than half the operating wavelength therefrom and means interposed between said reflector and said radiating means for re-distributing the field within said reflector for most effective use of the surface of said reflector.
2. An antenna system comprising radiating means within a parabolic reflector, a flat shading element disposed across the opening of said reflector in front of said radiator means at a distance less than half the operating wavelength therefrom and means interposed between said reflector and said radiating means for limiting the effective surface of said refle tor, said last means comprising a right circular cone.
3. An antenna system comprising radiating means within a parabolic reflector, a flat shading disc disposed across the opening of said reflector in front of said radiator means at a distance less than half the operating wavelength therefrom and means interposed between said reflector and said radiating means for limiting the effective surface of said reflector, said last means comprising a right circular cone having a side equal in length to a half of the operating wavelength.
4. An antenna system comprising radiating means within a parabolic reflector, a flat shading disc disposed across the opening of said reflector in front of said radiator means at a distance less than half the operating wavelength therefrom and means interposed between said reflector and said radiating means for re-distributing the fleld within said reflector for most effective use of the surface of said reflector, said last m ans comprising a right circular cone having a side equal in length to a half of the operating wavelength.
5. An antenna system comprising radiating means within a parabolic reflector and means interposed between said reflector and said radiating means for distributing the fleld within said reflector for a most effective use of the surface of said reflector, said means comprising a conductive cone, the apex of said cone facing said radiating means, said cone having a side length of the order of one-half of the operating wavelength of said system.
6. An antenna system comprising electromagnetic radiating means within a parabolic reflector and means interposed between said radiating means and a portion of said reflector for limiting the distribution of radiated energy to predetermined portions of said reflector, said means comprising a conductive body tapering from said reflector toward said radiating means, the length of the tapering side of said body being of the order of one-half of the operating wavelength of said system.
7. The combination with a radio frequency radiator and wave directive structure for concentrating radiation from said radiator in a given direction of means interposed between said radiator and a portion of said structure for limiting distribution of radiated energy from said radiator to predetermined portions of said structure, said means including a conductive body tapering from said structure toward said radiator the length of said conductive body being of the order of one-half of the operating wavelength of said radiator.
8. An antenna system comprising radiator means within a parabolic reflector and means interposed between said reflector and said radiator means for distributing the field within said reflector for a most effective use of the surface of said reflector, said means comprising a right circular conductive cone, the apex of said cone facing said radiator means, said cone having a side length of the order of one-half of the operating Wavelength of said system.
9. An ant nna system including radiating means within a parabolic reflector, a flat shading element disposed across the opening of said reflector in front of said radiating means, and means interposed between said reflector and said radiating means for re-distributing the fleld within said reflector for the most effective use of the surface of said reflector, said last-mentioned means including a conductive cone, the apex of said cone facing said radiating means.
NILS E. LINDENBLAD.
US372609A 1940-12-31 1940-12-31 Directive antenna system Expired - Lifetime US2370053A (en)

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Cited By (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2440210A (en) * 1946-03-26 1948-04-20 Us Sec War Antenna
US2477694A (en) * 1940-06-15 1949-08-02 Csf Radio waves radiators
US2478913A (en) * 1944-02-07 1949-08-16 Stromberg Carlson Co Dipole antenna
US2482158A (en) * 1945-07-21 1949-09-20 Bell Telephone Labor Inc Directive antenna system
US2483575A (en) * 1944-07-26 1949-10-04 Bell Telephone Labor Inc Directional microwave antenna
US2485138A (en) * 1946-10-03 1949-10-18 Rca Corp High-gain antenna system
US2486589A (en) * 1945-02-27 1949-11-01 Us Navy Apple-core reflector antenna
US2508438A (en) * 1945-10-16 1950-05-23 Douglas W Wilson Broad band antenna
US2510020A (en) * 1947-10-28 1950-05-30 Rca Corp Reflector for radar navigation
US2509283A (en) * 1945-10-25 1950-05-30 Rca Corp Directive antenna system
US2520945A (en) * 1943-08-18 1950-09-05 Sperry Corp Wave transmission apparatus
US2531455A (en) * 1942-02-04 1950-11-28 Sperry Corp Directive antenna structure
US2534289A (en) * 1942-10-17 1950-12-19 Sperry Corp Wave guide impedance matching section
US2549143A (en) * 1947-11-06 1951-04-17 Bell Telephone Labor Inc Microwave broadcast antenna
US2552162A (en) * 1941-11-26 1951-05-08 Gen Electric Cable terminating device
US2556046A (en) * 1946-03-28 1951-06-05 Philco Corp Directional antenna system
US2586827A (en) * 1945-03-31 1952-02-26 Sperry Corp Directive radiating system
US2605419A (en) * 1945-10-11 1952-07-29 Lester C Van Atta Wave guide feed for illuminating parabolic reflectors
US2605415A (en) * 1945-09-14 1952-07-29 Samuel J Mason Parabolic reflector
US2624836A (en) * 1945-08-30 1953-01-06 Robert H Dicke Radio noise transmitter
US2625655A (en) * 1952-08-26 1953-01-13 Marvin P Middlemark High-frequency system employing a reflector
US2627028A (en) * 1945-07-03 1953-01-27 Welville B Nowak Antenna system
US2671854A (en) * 1945-09-06 1954-03-09 Halpern Julius Conical scanning antenna
US2671855A (en) * 1945-09-19 1954-03-09 Lester C Van Atta Antenna
US2682048A (en) * 1945-04-07 1954-06-22 Us Sec War Radio object detection apparatus
US2759182A (en) * 1945-03-24 1956-08-14 Bell Telephone Labor Inc Directive antenna systems
DE953710C (en) * 1953-08-26 1956-12-06 Patelhold Patentverwertung Directional microwave antenna system
US2846679A (en) * 1953-12-15 1958-08-05 Hughes Aircraft Co Beam forming antenna
US3009154A (en) * 1957-09-05 1961-11-14 Philco Corp Directive antenna system
US3133284A (en) * 1959-03-02 1964-05-12 Rca Corp Paraboloidal antenna with compensating elements to reduce back radiation into feed
US3162858A (en) * 1960-12-19 1964-12-22 Bell Telephone Labor Inc Ring focus antenna feed
US3965455A (en) * 1974-04-25 1976-06-22 The United States Of America As Represented By The Secretary Of The Navy Focused arc beam transducer-reflector
US4178576A (en) * 1977-09-01 1979-12-11 Andrew Corporation Feed system for microwave antenna employing pattern control elements
US4689632A (en) * 1985-05-30 1987-08-25 Rca Corporation Reflector antenna system having reduced blockage effects
US4982198A (en) * 1988-05-16 1991-01-01 Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of National Defence High performance dipole feed for reflector antennas

Cited By (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2477694A (en) * 1940-06-15 1949-08-02 Csf Radio waves radiators
US2552162A (en) * 1941-11-26 1951-05-08 Gen Electric Cable terminating device
US2531455A (en) * 1942-02-04 1950-11-28 Sperry Corp Directive antenna structure
US2534289A (en) * 1942-10-17 1950-12-19 Sperry Corp Wave guide impedance matching section
US2520945A (en) * 1943-08-18 1950-09-05 Sperry Corp Wave transmission apparatus
US2478913A (en) * 1944-02-07 1949-08-16 Stromberg Carlson Co Dipole antenna
US2483575A (en) * 1944-07-26 1949-10-04 Bell Telephone Labor Inc Directional microwave antenna
US2486589A (en) * 1945-02-27 1949-11-01 Us Navy Apple-core reflector antenna
US2759182A (en) * 1945-03-24 1956-08-14 Bell Telephone Labor Inc Directive antenna systems
US2586827A (en) * 1945-03-31 1952-02-26 Sperry Corp Directive radiating system
US2682048A (en) * 1945-04-07 1954-06-22 Us Sec War Radio object detection apparatus
US2627028A (en) * 1945-07-03 1953-01-27 Welville B Nowak Antenna system
US2482158A (en) * 1945-07-21 1949-09-20 Bell Telephone Labor Inc Directive antenna system
US2624836A (en) * 1945-08-30 1953-01-06 Robert H Dicke Radio noise transmitter
US2671854A (en) * 1945-09-06 1954-03-09 Halpern Julius Conical scanning antenna
US2605415A (en) * 1945-09-14 1952-07-29 Samuel J Mason Parabolic reflector
US2671855A (en) * 1945-09-19 1954-03-09 Lester C Van Atta Antenna
US2605419A (en) * 1945-10-11 1952-07-29 Lester C Van Atta Wave guide feed for illuminating parabolic reflectors
US2508438A (en) * 1945-10-16 1950-05-23 Douglas W Wilson Broad band antenna
US2509283A (en) * 1945-10-25 1950-05-30 Rca Corp Directive antenna system
US2440210A (en) * 1946-03-26 1948-04-20 Us Sec War Antenna
US2556046A (en) * 1946-03-28 1951-06-05 Philco Corp Directional antenna system
US2485138A (en) * 1946-10-03 1949-10-18 Rca Corp High-gain antenna system
US2510020A (en) * 1947-10-28 1950-05-30 Rca Corp Reflector for radar navigation
US2549143A (en) * 1947-11-06 1951-04-17 Bell Telephone Labor Inc Microwave broadcast antenna
US2625655A (en) * 1952-08-26 1953-01-13 Marvin P Middlemark High-frequency system employing a reflector
DE953710C (en) * 1953-08-26 1956-12-06 Patelhold Patentverwertung Directional microwave antenna system
US2846679A (en) * 1953-12-15 1958-08-05 Hughes Aircraft Co Beam forming antenna
US3009154A (en) * 1957-09-05 1961-11-14 Philco Corp Directive antenna system
US3133284A (en) * 1959-03-02 1964-05-12 Rca Corp Paraboloidal antenna with compensating elements to reduce back radiation into feed
US3162858A (en) * 1960-12-19 1964-12-22 Bell Telephone Labor Inc Ring focus antenna feed
US3965455A (en) * 1974-04-25 1976-06-22 The United States Of America As Represented By The Secretary Of The Navy Focused arc beam transducer-reflector
US4178576A (en) * 1977-09-01 1979-12-11 Andrew Corporation Feed system for microwave antenna employing pattern control elements
US4689632A (en) * 1985-05-30 1987-08-25 Rca Corporation Reflector antenna system having reduced blockage effects
US4982198A (en) * 1988-05-16 1991-01-01 Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of National Defence High performance dipole feed for reflector antennas

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