US3881178A - Antenna system for radiating multiple planar beams - Google Patents

Antenna system for radiating multiple planar beams Download PDF

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Publication number
US3881178A
US3881178A US347505A US34750573A US3881178A US 3881178 A US3881178 A US 3881178A US 347505 A US347505 A US 347505A US 34750573 A US34750573 A US 34750573A US 3881178 A US3881178 A US 3881178A
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US
United States
Prior art keywords
reflector
focal axis
plane
antenna system
planar
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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
US347505A
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English (en)
Inventor
Peter W Hannan
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.)
BAE Systems Aerospace Inc
Original Assignee
Hazeltine Corp
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 Hazeltine Corp filed Critical Hazeltine Corp
Priority to US347505A priority Critical patent/US3881178A/en
Priority to GB650574A priority patent/GB1425142A/en
Priority to CA192,580A priority patent/CA991742A/en
Priority to AU65690/74A priority patent/AU482517B2/en
Priority to SE7402999A priority patent/SE394924B/xx
Priority to IL44496A priority patent/IL44496A/en
Priority to NL7404187A priority patent/NL7404187A/xx
Priority to FR7410815A priority patent/FR2224888B1/fr
Priority to DE2415020A priority patent/DE2415020A1/de
Priority to JP49036865A priority patent/JPS49131359A/ja
Priority to DD177598A priority patent/DD110956A5/xx
Priority to IT42614/74A priority patent/IT1010886B/it
Priority to PL1974170021A priority patent/PL94574B1/pl
Priority to BR2610/74A priority patent/BR7402610D0/pt
Priority to CS742399A priority patent/CS187412B2/cs
Application granted granted Critical
Publication of US3881178A publication Critical patent/US3881178A/en
Priority to JP1982087317U priority patent/JPS586410U/ja
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
    • G01S1/02—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using radio waves
    • G01S1/08—Systems for determining direction or position line
    • G01S1/38—Systems for determining direction or position line using comparison of [1] the phase of the envelope of the change of frequency, due to Doppler effect, of the signal transmitted by an antenna moving, or appearing to move, in a cyclic path with [2] the phase of a reference signal, the frequency of this reference signal being synchronised with that of the cyclic movement, or apparent cyclic movement, of the antenna
    • G01S1/40—Systems for determining direction or position line using comparison of [1] the phase of the envelope of the change of frequency, due to Doppler effect, of the signal transmitted by an antenna moving, or appearing to move, in a cyclic path with [2] the phase of a reference signal, the frequency of this reference signal being synchronised with that of the cyclic movement, or apparent cyclic movement, of the antenna the apparent movement of the antenna being produced by cyclic sequential energisation of fixed antennas
    • 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
    • H01Q19/06—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 refracting or diffracting devices, e.g. lens
    • H01Q19/062—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 refracting or diffracting devices, e.g. lens for focusing
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q25/00—Antennas or antenna systems providing at least two radiating patterns
    • H01Q25/007—Antennas or antenna systems providing at least two radiating patterns using two or more primary active elements in the focal region of a focusing device

Definitions

  • the present invention relates to a multiple beam antenna suitable for use in an antenna system for radiating a Doppler coded pattern such as described in copending application Ser. No. 347.506. filed Apr. 3. 1973. entitled Antenna System For Radiating Doppler Coded Pattern Using Multiple Beam Antenna and assigned to the same assignee as the present application.
  • This invention relates to antennas for use in direction finding systems.
  • antenna systems capable of radiating multiple simultaneous planar beams.
  • Direction finding systems generally measure the angular components of a direction vector to a target in either planar or conical coordinates; for example, it is usual to specify azimuth direction of a target in planar coordinates and elevation angle in conical coordinates.
  • Modern direction finding systems require antennas which have very rapid beam motion or can operate with many simultaneous beams. These features enable rapid movement of the beam between targets. or enable the antenna to have simultaneous beams on more than one target.
  • a well known antenna system for locating targets in a planar coordinate system is a mechanically rotated fan beam" antenna commonly used for search radars and other applications.
  • This antenna type may take the form of a specially shaped reflector and illuminating feed or a linear array of antenna elements with wave signals of equal phase coupled to each element. Either of these antennas radiates a single planar fan beam which is moved through space by mechanically rotating the antenna.
  • Prior antenna systems with multiple fan beams include linear arrays of antenna elements which achieve these beams by changing the phase of the energy coupled to each of the elements.
  • Another multiple fan beam system is a paraboloid reflector with a large aspect ratio and multiple feeds. Both of these systems provide conical beams.
  • a circular array of antenna elements is capable of providing multiple planar fan beams.
  • This antenna system requires. however, a large number of antenna elements and many complex circuit devices to achieve accurate direction finding.
  • Another disadvantage is that the circular array must usually have a diameter larger than the useful aperture.
  • An object of the present invention is to provide an antenna system for simultaneously radiating a plurality of planar beams into an assigned region of space.
  • a further object of the present invention is to provide such an antenna system which will radiate focused wave energy over a desired radiation angle for each planar beam.
  • a still further object of the present invention is to provide such an antenna system in a simple configuration and at a low cost.
  • an antenna system for radiating a plurality of planar beams and having a desired radiation angle in the plane of each beam.
  • the antenna system includes a cylindrical reflector for converting an incident spherical wave from a point source into a cylindrical wave. the reflector having an axial length which subtends an angle. viewed from a point on the focal axis of the reflector which is substantially equal to the desired radiation angle. Further included are a number of feed elements. equal to the number of planar beams desired and each oriented to efficiently illuminate the reflector with wave energy patterns.
  • the feed elements are located in the vicinity of the point on the focal axis and have in a plane which is perpendicular to the focal axis a component of angle displacement from each other. viewed from the center of the reflector.
  • a corresponding planar beam will be radiated in a direction which is unique to that beam when observed in a plane perpendicular to the focal axis. and having the desired radiation angle in the plane of that beam.
  • FIG. 1 is one embodiment of an antenna system constructed in accordance with the present invention.
  • FIG. 2 illustrates. the planar beams radiated by the FIG. 1 antenna.
  • FIG. 3 and 4 are alternative embodiments of the present invention.
  • the antenna system of FIG. 1 includes focusing means for converting an incident spherical wave from a point source into acylindrical wave, namely, a parabolic cylindrical reflector l0. and means for illuminating the focusing means with wave energy patterns which in this embodiment comprises the three feedhorns 11a. b. c.
  • the reflector l0 has a focal axis 12 and an axial length 13 such that the axial length 13 subtends an angle 14 when viewed from a point IS on the focal axis 12.
  • the feedhorns II in the FIG. 1 embodiment are located in the vicinity of the point 15 on the focal axis 12 and have a component of angular displacement 16 from each other in a plane 17, which is perpendicular to the focal axis 12, when viewed from the center 18 of the reflector 10.
  • the height 19 of the reflector l and the'distance to the focal axis 12 are chosen in accordance with standard principles well known to those skilled in the antenna art, and on the basis of desired beamwidth in the plane 17 perpendicular to the focal axis 12 and the characteristic patterns of the feedhorns II.
  • the width 13 of the reflector is chosen such that angle 14 is substantially equal to the desired radiation angle of the planar beams to be radiated as measured in the plane of each beam.
  • Feedhorns 11 may be of any suitable type that will radiate wave energy patterns which efficiently illuminate the reflector l0. Feed elements other than feedhorns 11 may very well be used as is evident to one skilled in the art. Other types of elements which may be used are dipoles and spirals.
  • the wave energy patterns from each of the feedhorns have a radiation phase center at a different point in space.
  • the radiation phase center is the point in space from which spherically diverging waves appear to originate.
  • Other means for illuminating the reflector 10 with the necessary plurality of wave energy patterns are possible.
  • One such means is the apparatus described in U.S. Pat. No. 3,710,388, which is an array of elements having the capability of radiating wave energy patterns from phase centers displaced in space.
  • the feedhorns 11 are located substantially in a plane 17 which passes through the center of the reflector l0 and is perpendicular to the focal axis 12.
  • the feed locations may be displaced to one side of center. This would be likely in a system wherein asymmetrical coverage is required. It is also not required that the feed elements be located in plane 17, so long as they have the required component of angular displacement 16 in the plane 17.
  • FIG. 2 The operation of the FIG. 1 antenna is illustrated in FIG. 2.
  • a corresponding planar beam 20 is radiated in a direction which is unique to that feedhorn when measured in a plane 17 perpendicular to the focal axis 12.
  • Each of the planar beams 20a, 12, c so radiated has a desired radiation angle 21 in the plane of that beam corresponding to the angle 14 subtended by the axial length 13 of the reflector 10 as shown in FIG. 1.
  • These planar beams 20 radiated by the antenna system of FIG. 1 are suitable for use in a direction finding system using planar coordinates.
  • the reflector 10 in FIG. 1 may be replaced with any one of many devices that are capable of converting an incident spherical wave from a point source into a cylindrical wave, including transmissive lenses and arrays.
  • Such focusing means have a substantial focusing effect on incident wave energy in one plane which includes the direction of propagation and no substantial focusing effect in a perpendicular plane which also includes the direction of propagation.
  • the plane in which focusing occurs is perpendicular to the focal axis of the focusing means.
  • spherically diverging waves originating from a point source in the vicinity of the focal axis are converted by such focusing means to cylindrically diverging waves as would originate from a line source of radiation.
  • the parabolic reflector 10 in the FIG. 1 embodiment has only one focal axis 12.
  • a transmissive focusing means for converting an incident spherical wave from a point source into a cylindrical wave, such as a dielectric lens, has two focal axes, one on each side of the lens.
  • a circularly symmetrical focusing means such as a circular cylindrical reflector or a cylindrical Luneberg lens has an infinite number of focal axes by reason of its circular symmetry.
  • a point on any focal axis may be used as a reference for locating the necessary illuminating means.
  • FIG. 3 is an embodiment of the present invention wherein the focusing means is transmissive and is a cylindrical Luneberg lens 22.
  • the most commonly known Luneberg lens is a spherical structure of material whose propagation velocity is a function of the radius at which the material is located, such that incident plane wave energy is focused to a point on the surface of the sphere diametrically opposite the point corresponding to the direction of incidence.
  • the cylindrical Luneberg lens 22 causes incident plane wave energy to be focused to an axial line on the surface diametrically opposite the axial line corresponding to the direction of incidence.
  • the cylindrical Luneberg lens 22 is therefore capable of focusing incident wave energy with respect to an infinite number of focal axes due to its circular symmetry.
  • the feedhorns llu, b, c are located on the surface of the lens 22 in the vicinity of a particular focal axis 12'.
  • the feedhorns 11 have an angular displacement component 16' from each other in a plane 17, which is perpendicular to the focal axis 12, viewed from the center 18 of the lens 22.
  • the lens 22 has an axial length 13' which on the surface diametrically opposite the focal axis 12 subtends an angle substantially equal to the desired radiation angle, viewed from a point on the focal axis 12' in the vicinity of the feedhorns 11.
  • FIG. 4 is another embodiment of the present invention wherein the focusing means is a transmissive array structure 26.
  • the array structure 26 includes a first array of receiving elements 23 for receiving the wave energy patterns from the feedhorns 11.
  • the structure 26 also includes means 24 for shifting the phase of the wave energy received by each of the elements 23 of the first array and a second array of elements 25 for radiating the phase shifted wave energy.
  • the phase shifting means 24 provide an appropriate predetermined amount of phase shift for each of the elements 23, such that the structure 22 performs the function of converting an incident spherical wave from a point source into a cylindrical wave.
  • the phase shifting means 24 may be any of the commonly used devices such as variable lengths of transmission line or transmission line with variable amounts of dielectric loading.
  • the array elements 23 and may be any of those commonly used in the art, such as dipoles, horns or spirals.
  • phase shifting means 24 used in the HO. 4 embodiment may be reflective phase shifters which cause energy to re-radiate from the first array of elements 23, in which case the second array of elements 25 is not required.
  • the result is a reflective focusing means comprising an array of reflective elements.
  • An antenna constructed in accordance with the present invention can be used as a scanned beam antenna system as well as a multiple beam antenna system.
  • the scanned beam antenna is achieved by causing motion of the phase center of the illuminating means or by sequentially coupling each of the multiple feeds to the transmitter or receiver.
  • An antenna system for radiating a plurality of planar beams and having a desired radiation angle in the plane of each beam comprising:
  • a cylindrical reflector for converting an incident spherical wave from a point source into a cylindrical wave, said reflector having an axial length which subtends an angle, viewed from a point on the focal axis of said reflector, which is substantially equal to said desired radiation angle;
  • feed elements equal to the number of planar beams desired and each oriented to efficiently illuminate said reflector with a wave energy pattern, said feed elements being located in the vicinity of said point on said focal axis and having in a plane which is perpendicular to said focal axis a component of angular displacement from each other, viewed from the center of said reflector;
  • An antenna system for radiating a plurality of planar beams and having a desired radiation angle in the plane of each beam comprising:
  • a parabolic cylindrical reflector for converting an incident spherical wave from a point source into a cylindrical wave, and having an axial length which subtends an angle when viewed from a point on the focal axis of said parabolic reflector, which is sub stantially equal to said desired radiation angle;
  • a number of waveguide feedhorns equal to the number of planar beams desired and each oriented to efficiently illuminate said reflector with wave energy patterns, said feedhorns being located in the vicinity of said point on said focal axis and having in a plane which is perpendicular to said focal axis substantially equal components of angular displacement from each other, viewed from the center of said reflector;

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Aerials With Secondary Devices (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)
US347505A 1973-04-03 1973-04-03 Antenna system for radiating multiple planar beams Expired - Lifetime US3881178A (en)

Priority Applications (16)

Application Number Priority Date Filing Date Title
US347505A US3881178A (en) 1973-04-03 1973-04-03 Antenna system for radiating multiple planar beams
GB650574A GB1425142A (en) 1973-04-03 1974-02-13 Antenna system for radiating multiple planar beams
CA192,580A CA991742A (en) 1973-04-03 1974-02-14 Antenna system for radiating multiple planar beams
AU65690/74A AU482517B2 (en) 1973-04-03 1974-02-18 Antenna system for radiating multiple planar beams
SE7402999A SE394924B (sv) 1973-04-03 1974-03-06 Antennsystem for utstralning av ett flertal stralar
IL44496A IL44496A (en) 1973-04-03 1974-03-26 Antenna system for radiating multiple planar beams
NL7404187A NL7404187A (cs) 1973-04-03 1974-03-27
DE2415020A DE2415020A1 (de) 1973-04-03 1974-03-28 Antennensystem
FR7410815A FR2224888B1 (cs) 1973-04-03 1974-03-28
JP49036865A JPS49131359A (cs) 1973-04-03 1974-04-01
DD177598A DD110956A5 (cs) 1973-04-03 1974-04-01
IT42614/74A IT1010886B (it) 1973-04-03 1974-04-02 Sistema di antenna per irradiare fasci planari multipli
PL1974170021A PL94574B1 (pl) 1973-04-03 1974-04-02 Uklad antenowy promieniujacy wiele plaskich wiazek
BR2610/74A BR7402610D0 (pt) 1973-04-03 1974-04-02 Sistema de antena
CS742399A CS187412B2 (en) 1973-04-03 1974-04-03 Aerial system for emitting the higher number of the surface beams
JP1982087317U JPS586410U (ja) 1973-04-03 1982-06-11 多重平面ビ−ム輻射用空中線装置

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US347505A US3881178A (en) 1973-04-03 1973-04-03 Antenna system for radiating multiple planar beams

Publications (1)

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US3881178A true US3881178A (en) 1975-04-29

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US347505A Expired - Lifetime US3881178A (en) 1973-04-03 1973-04-03 Antenna system for radiating multiple planar beams

Country Status (14)

Country Link
US (1) US3881178A (cs)
JP (2) JPS49131359A (cs)
BR (1) BR7402610D0 (cs)
CA (1) CA991742A (cs)
CS (1) CS187412B2 (cs)
DD (1) DD110956A5 (cs)
DE (1) DE2415020A1 (cs)
FR (1) FR2224888B1 (cs)
GB (1) GB1425142A (cs)
IL (1) IL44496A (cs)
IT (1) IT1010886B (cs)
NL (1) NL7404187A (cs)
PL (1) PL94574B1 (cs)
SE (1) SE394924B (cs)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2631026A1 (de) * 1975-07-10 1977-02-10 Hazeltine Corp Antennensystem
US4172257A (en) * 1976-07-20 1979-10-23 Siemens Aktiengesellschaft Ground station antenna for satellite communication systems
US4439773A (en) * 1982-01-11 1984-03-27 Bell Telephone Laboratories, Incorporated Compact scanning beam antenna feed arrangement
US4482897A (en) * 1982-06-28 1984-11-13 At&T Bell Laboratories Multibeam segmented reflector antennas
US5686923A (en) * 1994-05-10 1997-11-11 Dasault Electronique Multi-beam antenna for receiving microwaves emanating from several satellites
US5995056A (en) * 1997-09-18 1999-11-30 United States Of America As Represented By The Secretary Of The Navy Wide band tem fed phased array reflector antenna
US6208312B1 (en) * 2000-03-15 2001-03-27 Harry J. Gould Multi-feed multi-band antenna
US6246375B1 (en) * 1998-12-24 2001-06-12 Murata Manufacturing Co., Ltd. Antenna device and transmit-receive unit using the same
WO2009050325A1 (en) * 2007-10-16 2009-04-23 Helsinki University Of Technology Reflectionless lens
US20110043403A1 (en) * 2008-02-27 2011-02-24 Synview Gmbh Millimeter wave camera with improved resolution through the use of the sar principle in combination with a focusing optic
US8558734B1 (en) * 2009-07-22 2013-10-15 Gregory Hubert Piesinger Three dimensional radar antenna method and apparatus

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59174830U (ja) * 1983-05-11 1984-11-22 福山　隆吉 温灸器
ES1008936Y (es) * 1989-01-31 1989-12-16 Televes S.A. Soporte para alimentadores de antenas parabolicas de recepcion multisatelite.
FR2681982B1 (fr) * 1991-09-26 1993-11-19 Alcatel Espace Antenne a balayage electronique.
RU2688949C1 (ru) 2018-08-24 2019-05-23 Самсунг Электроникс Ко., Лтд. Антенна миллиметрового диапазона и способ управления антенной

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US2437281A (en) * 1944-07-19 1948-03-09 Sperry Corp High-frequency radiant energy apparatus
US2663016A (en) * 1948-12-29 1953-12-15 Coligny Guerric De Pillot De Microwave antenna
US3016531A (en) * 1955-03-14 1962-01-09 Sperry Rand Corp Antenna distribution system
US3170158A (en) * 1963-05-08 1965-02-16 Rotman Walter Multiple beam radar antenna system
US3267472A (en) * 1960-07-20 1966-08-16 Litton Systems Inc Variable aperture antenna system
US3317912A (en) * 1963-07-29 1967-05-02 Kenneth S Kelleher Plural concentric parabolic antenna for omnidirectional coverage
US3341151A (en) * 1965-07-23 1967-09-12 Kampinsky Abe Apparatus providing a directive field pattern and attitude sensing of a spin stabilized satellite
US3406401A (en) * 1966-08-25 1968-10-15 Bell Telephone Labor Inc Communication satellite system
US3414904A (en) * 1966-05-16 1968-12-03 Hughes Aircraft Co Multiple reflector antenna
US3568184A (en) * 1965-10-14 1971-03-02 Thomson Houston Comp Francaise Directional antenna array having improved electronic directional control
US3775769A (en) * 1971-10-04 1973-11-27 Raytheon Co Phased array system

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2437281A (en) * 1944-07-19 1948-03-09 Sperry Corp High-frequency radiant energy apparatus
US2663016A (en) * 1948-12-29 1953-12-15 Coligny Guerric De Pillot De Microwave antenna
US3016531A (en) * 1955-03-14 1962-01-09 Sperry Rand Corp Antenna distribution system
US3267472A (en) * 1960-07-20 1966-08-16 Litton Systems Inc Variable aperture antenna system
US3170158A (en) * 1963-05-08 1965-02-16 Rotman Walter Multiple beam radar antenna system
US3317912A (en) * 1963-07-29 1967-05-02 Kenneth S Kelleher Plural concentric parabolic antenna for omnidirectional coverage
US3341151A (en) * 1965-07-23 1967-09-12 Kampinsky Abe Apparatus providing a directive field pattern and attitude sensing of a spin stabilized satellite
US3568184A (en) * 1965-10-14 1971-03-02 Thomson Houston Comp Francaise Directional antenna array having improved electronic directional control
US3414904A (en) * 1966-05-16 1968-12-03 Hughes Aircraft Co Multiple reflector antenna
US3406401A (en) * 1966-08-25 1968-10-15 Bell Telephone Labor Inc Communication satellite system
US3775769A (en) * 1971-10-04 1973-11-27 Raytheon Co Phased array system

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2631026A1 (de) * 1975-07-10 1977-02-10 Hazeltine Corp Antennensystem
US4172257A (en) * 1976-07-20 1979-10-23 Siemens Aktiengesellschaft Ground station antenna for satellite communication systems
US4439773A (en) * 1982-01-11 1984-03-27 Bell Telephone Laboratories, Incorporated Compact scanning beam antenna feed arrangement
US4482897A (en) * 1982-06-28 1984-11-13 At&T Bell Laboratories Multibeam segmented reflector antennas
US5686923A (en) * 1994-05-10 1997-11-11 Dasault Electronique Multi-beam antenna for receiving microwaves emanating from several satellites
US5995056A (en) * 1997-09-18 1999-11-30 United States Of America As Represented By The Secretary Of The Navy Wide band tem fed phased array reflector antenna
US6246375B1 (en) * 1998-12-24 2001-06-12 Murata Manufacturing Co., Ltd. Antenna device and transmit-receive unit using the same
US6208312B1 (en) * 2000-03-15 2001-03-27 Harry J. Gould Multi-feed multi-band antenna
WO2009050325A1 (en) * 2007-10-16 2009-04-23 Helsinki University Of Technology Reflectionless lens
US20110043403A1 (en) * 2008-02-27 2011-02-24 Synview Gmbh Millimeter wave camera with improved resolution through the use of the sar principle in combination with a focusing optic
US8558734B1 (en) * 2009-07-22 2013-10-15 Gregory Hubert Piesinger Three dimensional radar antenna method and apparatus

Also Published As

Publication number Publication date
FR2224888A1 (cs) 1974-10-31
CA991742A (en) 1976-06-22
DD110956A5 (cs) 1975-01-12
SE394924B (sv) 1977-07-18
FR2224888B1 (cs) 1980-04-25
IL44496A (en) 1976-10-31
BR7402610D0 (pt) 1974-11-05
CS187412B2 (en) 1979-01-31
JPS49131359A (cs) 1974-12-17
PL94574B1 (pl) 1977-08-31
IT1010886B (it) 1977-01-20
GB1425142A (en) 1976-02-18
JPS586410U (ja) 1983-01-17
NL7404187A (cs) 1974-10-07
DE2415020A1 (de) 1974-10-17
IL44496A0 (en) 1974-06-30
AU6569074A (en) 1975-08-21

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