US3736592A - Multiple beam retrodirective array with circular symmetry - Google Patents

Multiple beam retrodirective array with circular symmetry Download PDF

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US3736592A
US3736592A US00256856A US3736592DA US3736592A US 3736592 A US3736592 A US 3736592A US 00256856 A US00256856 A US 00256856A US 3736592D A US3736592D A US 3736592DA US 3736592 A US3736592 A US 3736592A
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retrodirective
antenna
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
    • H01Q3/44—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the electric or magnetic characteristics of reflecting, refracting, or diffracting devices associated with the radiating element
    • H01Q3/46—Active lenses or reflecting arrays
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
    • H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
    • H01Q3/2605—Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
    • H01Q3/2647—Retrodirective arrays
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q3/00—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system
    • H01Q3/26—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture
    • H01Q3/30—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array
    • H01Q3/34—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array by electrical means
    • H01Q3/40—Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture varying the relative phase between the radiating elements of an array by electrical means with phasing matrix

Definitions

  • ABSTRACT A method and apparatus for obtaining automatic, selective retrodirective performance from a circularly symmetric antenna array.
  • This system may be employed in an active or passive manner and accomplishes selective retrodirectivity by manipulation of beai'n'term'inals' of 'a multiple beam matrix which in turn controls a multimodal network.
  • the combination of the two matrix networks provide N separate beams from the circular antenna array. Also, by providing gain networks, control of the reradiated beam pattern is possible.
  • This system has the ability to identify the angle of incidence of any particular transmission, and is particularly suited for navigational beacon systems since the reradiated signal can provide bearing information in response to interrogation.
  • Van Atta shows a passive linear array of elements, interconnected in a manner such that an electromagnetic beam is radiated at substantially the same angle from which it came. It has become possible to construct an active Van Atta array, and thus, the use of such an array has been found to be an effective and practical way to obtain retrodirectivity.
  • the Van Atta array is basically limited to the linear or planar discrete arrays. Therefore, it effectively lacks the capability of operating with a circularly symmetric array, and is unable to provide 360 coverage.
  • An antenna system havingcircular symmetry is employed to provide automatic retrodirective performance.
  • This type of antenna includes N symmetrically spaced elements such .asdipoles, or spacedflslotsdisposed around a metallic periphery.
  • the antenna is connected by way of appropriate transmission lines to a multimodal N X N Butler feed network.
  • the network when properly fed, provides N separate and distinct beams around the array.
  • the feeding of the multimodal network takes place through I(( N) mode terminals" by way of a second Butler matrix.
  • Each mode terminal" is connected to the output of the second Butler matrix by way of an interconnecting line.
  • the N inputs to the second Butler matrix consists of N beam terminals and directly correspond to the separate N beams from the array.
  • Active circuitry may be connected to the beam terminals to provide active retrodirectivity. Also, by providing a processor to the active circuitry, unwanted signal characteristics may be inhibited. Finally, in both the active and passive systems, selective beam terminals may be terminated so as to inhibit response in un wanted directions.
  • An object of this invention is to provide an active or passive retrodirective circularly symmetric antenna system.
  • a further object is to provide a simple technique for controlling the properties of the reradiated beam.
  • Another object of this invention is to provide retrodirective performance by the use of a multiple beam circular array configuration.
  • a further object of the present invention is to provide a system which is capable of identifying the angle of incidence of a wavefront, upon retransmission, in the active configuration.
  • FIG. 1 shows a passive circularly symmetric retrodirective system
  • FIG. 2 shows the components required for active retro-directive performance
  • FIG. 3 is a diagram of the active retrodirective system capable of inhibiting unwanted signal characteristics.
  • the system includes circular antenna system 10, interconnecting lines 12, N X N Butler matrix 14, interconnecting lines 18 which connect mode terminals 16 to a second N X N Butler matrix 20.
  • Beam terminals 22 depend from Butler matrix 20.
  • the antenna 10 may be of a multitude of types including an array of N discrete radiating elements having circular symmetry; for example, an array of dipoles equally spaced and arranged on a circle concentric with a conducting cylinder.
  • the selection of any particular antenna system 10 largely depends upon the well known design considerations such as maximum or minimum size requirement, weight, gain, element spacing, and the other usual requirements.
  • the N number of interconnecting transmission lines 12 are employed as a means of connecting the N element array 10 to X N XN Butler matrix 14.
  • the lines could be made of coax cable or the like, and the selection of any particular interconnecting line 12 is unimportant to theoperation of the entire system as long as the interconnecting lines 12 are capable of accurately" maintaining amplitude and phase relationship information between the antenna system 10 and the N X N Butler matrix 14.
  • the N inputs of the N X N Butler matrix 14 provide the means for creating a phase progression at the antenna array 10 which results in N separate and distinct beams. Although, all N number of mode terminals may be connected to a second Butler matrix 20, this is not a necessary restriction. As shown in FIG. 1, K number of connections are effected between the output of the matrix 20 and the input of matrix 14 by way of K mode terminals 16.
  • the N X N Butler matrix 20 has N beam terminal inputs 22. When a unit voltage is applied to anyone of the N beam terminals (say the nth terminal) a beam corresponding to that particular terminal is generated in the d direction.
  • Connecting signal sources 25 to the set of beam terminals 22 results in a set of N beams cover the entire azimuth angle from qb to d) 360 such as shown in FIG. 2. If, however, the N beam terminals 22 are short circuited (or open circuited) a passive retrodirective array will result.
  • circuitry may be fitted to these terminals to provide an active retrodirective system, with great flexibility. This system is shown in FIG. 2. Although active circuitry 25 is only shown to be connected to selected beam terminals, it should be understood that an individual active element 25 may be connected to each of the N beam terminals.
  • the N active circuits 25 may be a circulator 24 connected to an amplifier 23 having a particular gain Gn. This arrangement provides amplification before reradiation so as to provide an enhanced response. Furthermore, the gains of the individual networks may be individually adjusted to give a tailored response with far field angle (1:. Also, amplifier circuitry 23 could also include a frequency translator or other similar device. Since the identification of particular beam terminals corresponds to the value of the far field angle 4), a change in reradiated signal characteristics yields a ready means of identifying the wavefronts angle of incidence. This information may be included in the retransmitted signal as bearing information or the like.
  • the array configuration provides a number of far field radiation patterns which are constant in amplitude but vary linearly with phase with far field angle tb. These patterns may be termed mode patterns and are available at the K mode terminals 16.
  • a processor 26 is shown to be connected to one of the omnidirectional mode ter minals by way of line 30.
  • One application of this configuration is in inhibiting the response of the retrodirective system for unwanted signal characteristics, (as determined by the processor) by means of crossconnection 32 to the active circuit 28.
  • the array shown in the figures may be arranged axially to form linear array of these circular subarrays. If corresponding beam terminals in such an axial array are interconnected, in the manner of a Van Atta, two dimensional retrodirective performance will result. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
  • a circularly symmetric retrodirective antenna system comprising:
  • a first N X N Butler feed network means having N inputs and N outputs wherein the N outputs are sequentially connected to said antenna means;
  • N X N Butler feed network means having N inputs and N outputs wherein at least a portion of the N outputs of said second feed network means are connected to inputs of the first feed network;
  • unity reflection coefficient means connected to a plurality of said N inputs of said second N X N feed network means with the remaining unconnected inputs being connected to matched loads such that retrodirectivity results from said antenna means in selector directions.
  • amplification means being coupled to said circulator means whereby active retrodirectivity results from said antenna means.

Abstract

A method and apparatus for obtaining automatic, selective retrodirective performance from a circularly symmetric antenna array. This system may be employed in an active or passive manner and accomplishes selective retrodirectivity by manipulation of beam terminals of a multiple beam matrix which in turn controls a multimodal network. The combination of the two matrix networks provide N separate beams from the circular antenna array. Also, by providing gain networks, control of the reradiated beam pattern is possible. This system has the ability to identify the angle of incidence of any particular transmission, and is particularly suited for navigational beacon systems since the reradiated signal can provide bearing information in response to interrogation.

Description

United States Patent [191 Coleman May 29, 1973 MULTIPLE BEAM RETRODIRECTIVE ARRAY WITH CIRCULAR SYMMETRY II. Paris Coleman, Alexandria, Va.
The United States of America as represented by the Secretary of the Navy, Washington, DC
May 25, 1972 Inventor:
Assignee:
Filed:
Appl. N0.:
US. Cl ..343/854, 343/777 Int. Cl. ..H01q 3/26 Field of Search ..343/777, 778, 779,
References Cited UNITED STATES PATENTS Lowe ..343/854 Primary Examiner-Eli Lieberman Attorney-R. S. Sciascia. Arthur L. Branning and Philip Schneider et aI.
ABSTRACT A method and apparatus for obtaining automatic, selective retrodirective performance from a circularly symmetric antenna array. This system may be employed in an active or passive manner and accomplishes selective retrodirectivity by manipulation of beai'n'term'inals' of 'a multiple beam matrix which in turn controls a multimodal network. The combination of the two matrix networks provide N separate beams from the circular antenna array. Also, by providing gain networks, control of the reradiated beam pattern is possible. This system has the ability to identify the angle of incidence of any particular transmission, and is particularly suited for navigational beacon systems since the reradiated signal can provide bearing information in response to interrogation.
2 Claims, 3 Drawing Figures INTERCONNECTING TRANSMISSION LINES l2 2K 5 N MODE TERMINALS I6 XN BUTLER MATRIX Q N BEAM TERMINALS Patented May 29, 1973 2 Sheets-Sheet l INTERCONNECTING TRANSMISSION LINES I2 zKsN MODE TERMINALS 0 0 l6 NXN BUTLER MATRIX g2 N BEAM TERMINALS FIG. l l l 22 MM L8 NXN BUTLER MATRIX 2Q l N BEAM TERMINALS FIG. 2. n
Patented May 29, 1973 3,736,592
2 Sheets-Sheet 2 ANTENNA J ARRAY INTERCONNECTING TRANSMISSION LINES I2 NxN BUTLER MATRIX 30 O Q 0 l ,I I K- -N MODE TERMINALS r I6 48- I8 NxN BUTLER PROCESSOR MATRIX I I l N BEAM TERMINALS I p 24 I l r-a2 I L a I! 28 MULTIPLE BEAM RETRODIRECTIVE ARRAY WITH CIRCULAR SYMMETRY STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION The most well known method of obtaining retrodirective beam radiation capability is disclosed by Van Atta in US. Pat. No. 2,908,002. Van Atta shows a passive linear array of elements, interconnected in a manner such that an electromagnetic beam is radiated at substantially the same angle from which it came. It has become possible to construct an active Van Atta array, and thus, the use of such an array has been found to be an effective and practical way to obtain retrodirectivity. However, the Van Atta array is basically limited to the linear or planar discrete arrays. Therefore, it effectively lacks the capability of operating with a circularly symmetric array, and is unable to provide 360 coverage.
Another method of obtaining retrodirective performance is explained in IEEE Transaction on Antennas and Propagation, March 1964, entitled Self-Phasing Array Antennas by M. Skolnik and D. King. This system operates on the incident wavefront in such a manner that when it is retransmitted it returns whence it came as a coherent wavefront, irrespective of the original phase distribution incident on the array. Although this method is applicable to very general arrays, information regarding the angle of arrival cannot be made available as a result of an interrogation.
Finally, a retrodirective circularly symmetric antenna system has been described in my copending application ser. No. 220,663, filed Jan. 25, 1972. Although 360 retrodirectivity is possible, as is control of the beam pattern, that device lacks flexibility when compared to this system. For example, particular sectors of this system may be inhibited from response, and additionally, a ready means of identifying the original angle or incidence upon retransmission is provided herein.
SUMMARY OF THE INVENTION An antenna system havingcircular symmetry is employed to provide automatic retrodirective performance. This type of antenna includes N symmetrically spaced elements such .asdipoles, or spacedflslotsdisposed around a metallic periphery.
The antenna is connected by way of appropriate transmission lines to a multimodal N X N Butler feed network. The network, when properly fed, provides N separate and distinct beams around the array. The feeding of the multimodal network takes place through I(( N) mode terminals" by way of a second Butler matrix. Each mode terminal" is connected to the output of the second Butler matrix by way of an interconnecting line. The N inputs to the second Butler matrix consists of N beam terminals and directly correspond to the separate N beams from the array.
Active circuitry may be connected to the beam terminals to provide active retrodirectivity. Also, by providing a processor to the active circuitry, unwanted signal characteristics may be inhibited. Finally, in both the active and passive systems, selective beam terminals may be terminated so as to inhibit response in un wanted directions.
OBJECTS OF THE INVENTION An object of this invention is to provide an active or passive retrodirective circularly symmetric antenna system.
A further object is to provide a simple technique for controlling the properties of the reradiated beam.
Another object of this invention is to provide retrodirective performance by the use of a multiple beam circular array configuration.
A further object of the present invention is to provide a system which is capable of identifying the angle of incidence of a wavefront, upon retransmission, in the active configuration.
Other objects of the invention will be readily apparent to those skilled in the art by referring to the following detailed description in connection with accompanying drawings wherein:
THE DRAWINGS FIG. 1 shows a passive circularly symmetric retrodirective system; and
FIG. 2 shows the components required for active retro-directive performance; and
FIG. 3 is a diagram of the active retrodirective system capable of inhibiting unwanted signal characteristics.
DETAILED DESCRIPTION Referring to FIG. 1, the system includes circular antenna system 10, interconnecting lines 12, N X N Butler matrix 14, interconnecting lines 18 which connect mode terminals 16 to a second N X N Butler matrix 20. Beam terminals 22 depend from Butler matrix 20.
The antenna 10 may be of a multitude of types including an array of N discrete radiating elements having circular symmetry; for example, an array of dipoles equally spaced and arranged on a circle concentric with a conducting cylinder. The selection of any particular antenna system 10 largely depends upon the well known design considerations such as maximum or minimum size requirement, weight, gain, element spacing, and the other usual requirements.
The N number of interconnecting transmission lines 12 are employed as a means of connecting the N element array 10 to X N XN Butler matrix 14. The lines could be made of coax cable or the like, and the selection of any particular interconnecting line 12 is unimportant to theoperation of the entire system as long as the interconnecting lines 12 are capable of accurately" maintaining amplitude and phase relationship information between the antenna system 10 and the N X N Butler matrix 14.
The N inputs of the N X N Butler matrix 14 provide the means for creating a phase progression at the antenna array 10 which results in N separate and distinct beams. Although, all N number of mode terminals may be connected to a second Butler matrix 20, this is not a necessary restriction. As shown in FIG. 1, K number of connections are effected between the output of the matrix 20 and the input of matrix 14 by way of K mode terminals 16. The N X N Butler matrix 20 has N beam terminal inputs 22. When a unit voltage is applied to anyone of the N beam terminals (say the nth terminal) a beam corresponding to that particular terminal is generated in the d direction.
Connecting signal sources 25 to the set of beam terminals 22 results in a set of N beams cover the entire azimuth angle from qb to d) 360 such as shown in FIG. 2. If, however, the N beam terminals 22 are short circuited (or open circuited) a passive retrodirective array will result.
To understand the principle of operation, consider a plane wave incident upon the array from the (1: direction. This plane wave results in voltages appearing at the set of beam terminals 22 which are proportional in amplitude and having the same relative phase that would have been required from the original set of signal sources to produce a beam in the 4) 4),, direction. Thus, if unity reflection coefficient terminations are provided at the set of beam terminals 22, incident energy is retransmitted with correct amplitude and phase relationship to cause a beam to reradiate in the d) (1) direction. If it is desirable to inhibit response in a particular sector, the sequence of beam terminals which correspond to that sector may be terminated in matched loads.
Instead of simply terminating the set of beam terminals to provide a passive response as shown in FIG. 1, circuitry may be fitted to these terminals to provide an active retrodirective system, with great flexibility. This system is shown in FIG. 2. Although active circuitry 25 is only shown to be connected to selected beam terminals, it should be understood that an individual active element 25 may be connected to each of the N beam terminals.
Typically, the N active circuits 25 may be a circulator 24 connected to an amplifier 23 having a particular gain Gn. This arrangement provides amplification before reradiation so as to provide an enhanced response. Furthermore, the gains of the individual networks may be individually adjusted to give a tailored response with far field angle (1:. Also, amplifier circuitry 23 could also include a frequency translator or other similar device. Since the identification of particular beam terminals corresponds to the value of the far field angle 4), a change in reradiated signal characteristics yields a ready means of identifying the wavefronts angle of incidence. This information may be included in the retransmitted signal as bearing information or the like.
Referring to FIG. 3, it should be noted that the array configuration provides a number of far field radiation patterns which are constant in amplitude but vary linearly with phase with far field angle tb. These patterns may be termed mode patterns and are available at the K mode terminals 16. A processor 26 is shown to be connected to one of the omnidirectional mode ter minals by way of line 30. One application of this configuration is in inhibiting the response of the retrodirective system for unwanted signal characteristics, (as determined by the processor) by means of crossconnection 32 to the active circuit 28.
Obviously many modifications and variations of the present invention are possible in light of the above teachings. For example, the array shown in the figures may be arranged axially to form linear array of these circular subarrays. If corresponding beam terminals in such an axial array are interconnected, in the manner of a Van Atta, two dimensional retrodirective performance will result. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
What is claimed and desired to be secured by Letters Patent of the United States is:
1. A circularly symmetric retrodirective antenna system comprising:
circular symmetric antenna means having N radiators, and
a first N X N Butler feed network means having N inputs and N outputs wherein the N outputs are sequentially connected to said antenna means; and
a second similar N X N Butler feed network means having N inputs and N outputs wherein at least a portion of the N outputs of said second feed network means are connected to inputs of the first feed network; and
unity reflection coefficient means connected to a plurality of said N inputs of said second N X N feed network means with the remaining unconnected inputs being connected to matched loads such that retrodirectivity results from said antenna means in selector directions.
2. The device as claimed in claim 1 wherein circulator means are connected to a plurality of said input terminals of said second network means; and
amplification means being coupled to said circulator means whereby active retrodirectivity results from said antenna means.

Claims (2)

1. A circularly symmetric retrodirective antenna system comprising: circular symmetric antenna means having N radiators; and a first N X N Butler feed network means having N inputs and N outputs wherein the N outputs are sequentially connected to said antenna means; and a second similar N X N Butler feed network means having N inputs and N outputs wherein at least a portion of the N outputs of said second feed network means are connected to inputs of the first feed network; and unity reflection coefficient means connected to a plurality of said N inputs oF said second N X N feed network means with the remaining unconnected inputs being connected to matched loads such that retrodirectivity results from said antenna means in selected directions.
2. The device as claimed in claim 1 wherein circulator means are connected to a plurality of said input terminals of said second network means; and amplification means being coupled to said circulator means whereby active retrodirectivity results from said antenna means.
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Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3997900A (en) * 1975-03-12 1976-12-14 The Singer Company Four beam printed antenna for Doopler application
US4032922A (en) * 1976-01-09 1977-06-28 The United States Of America As Represented By The Secretary Of The Navy Multibeam adaptive array
US4221948A (en) * 1976-11-17 1980-09-09 Jean Olivier A L Apparatus for subjecting a material to electromagnetic waves
US4338605A (en) * 1980-02-28 1982-07-06 Westinghouse Electric Corp. Antenna array with adaptive sidelobe cancellation
US4356461A (en) * 1981-01-14 1982-10-26 The Bendix Corporation Practical implementation of large Butler matrices
US4384290A (en) * 1979-04-26 1983-05-17 Thomson-Csf Airborne interrogation system
US4721960A (en) * 1986-07-15 1988-01-26 Canadian Marconi Company Beam forming antenna system
US4980692A (en) * 1989-11-29 1990-12-25 Ail Systems, Inc. Frequency independent circular array
US5064140A (en) * 1990-10-09 1991-11-12 The United States Of America As Represented By The Secretary Of The Army Covert millimeter wave beam projector
US20040160374A1 (en) * 2003-02-13 2004-08-19 Martin Johansson Feed network for simultaneous generation of narrow and wide beams with a rotational-symmetric antenna
US7567213B2 (en) * 2006-05-02 2009-07-28 Accton Technology Corporation Array structure for the application to wireless switch of WLAN and WMAN
US20100066590A1 (en) * 2008-07-28 2010-03-18 Physical Domains, LLC Omnidirectional Retrodirective Antennas
WO2014020592A1 (en) 2012-07-29 2014-02-06 Elta Systems Ltd. Transponder device
WO2014087398A1 (en) 2012-12-04 2014-06-12 Elta Systems Ltd. Rotatable transponder system
EP2846401A1 (en) * 2013-09-06 2015-03-11 John Howard Random, sequential, or simultaneous multi-beam circular antenna array and beam forming networks with up to 360° coverage
US20150244072A1 (en) * 2012-09-11 2015-08-27 Alcatel Lucent Multiband antenna with variable electrical tilt
US9374145B2 (en) * 2012-11-26 2016-06-21 Agence Spatiale Europeenne Beam-forming network for an array antenna and array antenna comprising the same
US20200411971A1 (en) * 2019-06-27 2020-12-31 Thales Two-dimensional analogue multibeam former of reduced complexity for reconfigurable active array antennas
US11855680B2 (en) * 2013-09-06 2023-12-26 John Howard Random, sequential, or simultaneous multi-beam circular antenna array and beam forming networks with up to 360° coverage

Families Citing this family (1)

* Cited by examiner, † Cited by third party
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US6664938B2 (en) 2002-03-01 2003-12-16 Ems Technologies Canada, Ltd. Pentagonal helical antenna array

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3295134A (en) * 1965-11-12 1966-12-27 Sanders Associates Inc Antenna system for radiating directional patterns

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3295134A (en) * 1965-11-12 1966-12-27 Sanders Associates Inc Antenna system for radiating directional patterns

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3997900A (en) * 1975-03-12 1976-12-14 The Singer Company Four beam printed antenna for Doopler application
US4032922A (en) * 1976-01-09 1977-06-28 The United States Of America As Represented By The Secretary Of The Navy Multibeam adaptive array
US4221948A (en) * 1976-11-17 1980-09-09 Jean Olivier A L Apparatus for subjecting a material to electromagnetic waves
US4339648A (en) * 1976-11-17 1982-07-13 Jean Olivier A L Process and apparatus for subjecting a material to electromagnetic waves
US4384290A (en) * 1979-04-26 1983-05-17 Thomson-Csf Airborne interrogation system
US4338605A (en) * 1980-02-28 1982-07-06 Westinghouse Electric Corp. Antenna array with adaptive sidelobe cancellation
US4356461A (en) * 1981-01-14 1982-10-26 The Bendix Corporation Practical implementation of large Butler matrices
US4721960A (en) * 1986-07-15 1988-01-26 Canadian Marconi Company Beam forming antenna system
US4980692A (en) * 1989-11-29 1990-12-25 Ail Systems, Inc. Frequency independent circular array
US5064140A (en) * 1990-10-09 1991-11-12 The United States Of America As Represented By The Secretary Of The Army Covert millimeter wave beam projector
US20040160374A1 (en) * 2003-02-13 2004-08-19 Martin Johansson Feed network for simultaneous generation of narrow and wide beams with a rotational-symmetric antenna
WO2004073111A1 (en) * 2003-02-13 2004-08-26 Telefonaktiebolaget Lm Ericsson (Publ) Feed network for simultaneous generation of narrow and wide beams with a rotational-symmetric antenna
US6791507B2 (en) 2003-02-13 2004-09-14 Telefonaktiebolaget Lm Ericsson (Publ) Feed network for simultaneous generation of narrow and wide beams with a rotational-symmetric antenna
CN1748340B (en) * 2003-02-13 2011-07-06 艾利森电话股份有限公司 Feed network for simultaneous generation of narrow and wide beams with a rotational-symmetric antenna
US7567213B2 (en) * 2006-05-02 2009-07-28 Accton Technology Corporation Array structure for the application to wireless switch of WLAN and WMAN
US20100066590A1 (en) * 2008-07-28 2010-03-18 Physical Domains, LLC Omnidirectional Retrodirective Antennas
US8344943B2 (en) * 2008-07-28 2013-01-01 Physical Domains, LLC Low-profile omnidirectional retrodirective antennas
US9229099B2 (en) * 2008-07-28 2016-01-05 Physical Domains, LLC Omnidirectional retrodirective antennas
US9134412B2 (en) 2012-07-29 2015-09-15 Elta Systems Ltd. Transponder device
WO2014020592A1 (en) 2012-07-29 2014-02-06 Elta Systems Ltd. Transponder device
US10103432B2 (en) * 2012-09-11 2018-10-16 Alcatel Lucent Multiband antenna with variable electrical tilt
US20150244072A1 (en) * 2012-09-11 2015-08-27 Alcatel Lucent Multiband antenna with variable electrical tilt
US9374145B2 (en) * 2012-11-26 2016-06-21 Agence Spatiale Europeenne Beam-forming network for an array antenna and array antenna comprising the same
WO2014087398A1 (en) 2012-12-04 2014-06-12 Elta Systems Ltd. Rotatable transponder system
US10998644B2 (en) 2012-12-04 2021-05-04 Elta Systems Ltd. Rotatable transponder system
US20150070241A1 (en) * 2013-09-06 2015-03-12 John Howard Random, sequential, or simultaneous multi-beam circular antenna array and beam forming networks with up to 360° coverage
EP2846401A1 (en) * 2013-09-06 2015-03-11 John Howard Random, sequential, or simultaneous multi-beam circular antenna array and beam forming networks with up to 360° coverage
US10734733B2 (en) * 2013-09-06 2020-08-04 John Howard Random, sequential, or simultaneous multi-beam circular antenna array and beam forming networks with up to 360° coverage
US11855680B2 (en) * 2013-09-06 2023-12-26 John Howard Random, sequential, or simultaneous multi-beam circular antenna array and beam forming networks with up to 360° coverage
US20200411971A1 (en) * 2019-06-27 2020-12-31 Thales Two-dimensional analogue multibeam former of reduced complexity for reconfigurable active array antennas
US11670840B2 (en) * 2019-06-27 2023-06-06 Thales Two-dimensional analogue multibeam former of reduced complexity for reconfigurable active array antennas

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