WO1998004017A1 - Systeme satellitaire geosynchrone de telecommunications a zone de desserte reconfigurable - Google Patents

Systeme satellitaire geosynchrone de telecommunications a zone de desserte reconfigurable Download PDF

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Publication number
WO1998004017A1
WO1998004017A1 PCT/US1997/012706 US9712706W WO9804017A1 WO 1998004017 A1 WO1998004017 A1 WO 1998004017A1 US 9712706 W US9712706 W US 9712706W WO 9804017 A1 WO9804017 A1 WO 9804017A1
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WO
WIPO (PCT)
Prior art keywords
satellite
array
coupled
elements
satellite system
Prior art date
Application number
PCT/US1997/012706
Other languages
English (en)
Inventor
John Wesley Locke
Paul Adrian Chiavacci
Keith Andrew Olds
Jeffrey C. Upton
Original Assignee
Motorola Inc.
Raytheon Company
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 Motorola Inc., Raytheon Company filed Critical Motorola Inc.
Publication of WO1998004017A1 publication Critical patent/WO1998004017A1/fr

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Classifications

    • 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
    • H01Q3/24—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 orientation by switching energy from one active radiating element to another, e.g. for beam switching
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q25/00—Antennas or antenna systems providing at least two radiating patterns
    • 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
    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/15—Active relay systems
    • H04B7/204—Multiple access
    • H04B7/2041—Spot beam multiple access

Definitions

  • This invention relates generally to satellite communications systems and, in particular, to a geosynchronous communications satellite system with a multi-beam phased array antenna capable of reconfiguring a service area.
  • GSO geosynchronous earth orbit
  • VSAT very small satellite earth terminals
  • USAT ultra small satellite earth terminals
  • These terminals use small, and therefore, relatively low gain antennas.
  • most of the lost earth terminal antenna gain cannot be compensated for with higher power transmitters.
  • the satellite must compensate for the lost earth terminal gain by increasing the gain of the satellite antenna, which of course reduces the area covered by each beam.
  • 20 GHz downlink / 30 GHz uplink requires approximately 500 to 1000 beams to cover an entire field of view from a GSO satellite, when the beams are sized to operate with low power earth terminals using sub-meter antennas. Since a practical conventional satellite antenna system can form about 100 beams, only about 10% of the field of view can be served. Thus, the market area that will be served must be predetermined and then the satellite antenna has to be custom designed according to the particular combination of orbital position ("slot") and service area. This approach carries at least four disadvantages. First, in a dynamic and uncertain market, there is the danger that the service location will be selected incorrectly, resulting in poor financial performance.
  • FIG. 1 shows antenna beams of a satellite covering a portion of the earth within the field-of-view of the satellite.
  • FIG. 2 shows a block diagram of components of a satellite according to a preferred embodiment of the present invention.
  • FIG. 3 shows a small square grid section of the radiating face of the arrays,
  • FIG. 4 shows a small triangular grid section of the radiating face of the arrays.
  • FIG. 5 shows components of each active element of a transmit array.
  • FIG. 6 shows components of each active element of a receive array.
  • FIG. 7 shows a portion of an embodiment of a multiple- beam beamformer.
  • FIG. 8 shows a network of eight 8-element column beamformers and eight 8-element row beamformers.
  • FIG. 9 shows a network of eight 8-element column combiners and eight 8-element row combiners.
  • FIG. 10 shows an 8 by 8 set of contiguous beams which are formed by a network.
  • FIG. 1 1 shows a portion of a second embodiment of a multiple-beam beamformer.
  • the present invention has utility in that a geosynchronous satellite system avoids the disadvantages listed above by combining phased array technology with onboard switching and control.
  • the satellite system comprises of a unique combination of three components: active transmit and receive phased array antennas with multiple beamformers (e.g., Butler matrices); beam selection switch matrices (one transmit, one receive); and a beam selection controller (commanded from the ground).
  • beamformers e.g., Butler matrices
  • beam selection switch matrices one transmit, one receive
  • a beam selection controller commanded from the ground.
  • multi-beam beamformers may comprise any beamformer which forms multiple orthogonal beams, including for example, Butler matrix beamformers (as described herein) and Rotman lens beamformers.
  • the satellite includes a communications payload and a conventional satellite bus.
  • the communications payload includes dynamic channel allocation capability so that capacity can be moved from one beam to another. This further enhances the capability of the satellite system to reconfigure the resources applied to the service area.
  • FIG. 1 shows antenna beams 12 of a satellite covering a portion of earth 10 within the field-of-view of the satellite.
  • the antenna beams 12 are selectable while the satellite is in orbit, for active communications with earth-based terminals.
  • the earth's disk 10 as seen from geosynchronous orbit is approximately +/- 8.7 degrees. Consequently, about 500 beams, each having 0.7 degrees beam width is required to fully cover the earth's disk as seen from a geosynchronous satellite.
  • a geosynchronous satellite is a satellite orbiting the earth at a distance of 35860 kilometers and remains directly over an assigned spot on the earth's equator.
  • FIG. 2 shows a block diagram of components 22-29 of a geosynchronous satellite system 20 according to a preferred embodiment of the present invention.
  • Components 22 -29 are just some of many components that comprise a satellite. For example, there are navigation components for positioning the satellite and power components for generating and maintaining power for the electronic components of satellite 20.
  • satellite system 20 comprises communications payload 22, switch controller 23, transmit switch matrix 24, receive switch matrix 25, Butler matrix beamformer 26 and 27, transmit phased array 28 and receive phased array 29.
  • Communications payload 22 receives L active beam signals to transmit switch matrix 24, and is responsible for selecting beam commands for switch controller 23.
  • Switch controller 23 receives selected beam commands from communications payload 22 and selects N beam ports for orthogonal (e.g., a Butler matrix) beamformer 26 and 27.
  • Transmit switch matrix 24 receives L active beam signals from N beam ports (selected by switch controller 23) from orthogonal (e.g., Butler matrix) beamformer 26 and transmit phased array 28.
  • Receive matrix 25 receives signals from N beam ports (selected by switch controller 23) from orthogonal beamformer 27 (e.g., Butler matrix) and transmits L active beams signals to communications payload 22.
  • Transmit phased array 28 and receive phased array 29 each comprises an array of a number of elements.
  • Transmit phased array 28 is responsible for transmitting radio frequency (RF) signals
  • receive phased array 29 is responsible for receiving RF signals from earth.
  • the RF signals may be data or voice signals.
  • a transmit multi-beam phased array 28 comprises an array of a number of active transmitting elements.
  • a receive multi-beam phased array 29 comprises an array of a number of active receiving elements.
  • FIG. 3 shows individual antenna elements in a square grid 30.
  • the individual transmitting antenna elements 32 are used.
  • individual receiving elements are used.
  • the transmit phased array 28 or receive phased array 29 can be positioned within an array aperture within the square grid 30 shown in FIG. 3 or in a triangular grid 40 as shown in FIG. 4.
  • FIG. 3 shows a small square grid section 30 of a face of an array, where the layout of the individual radiating elements in a square grid of columns and rows with each element 32 occupying a square section 34 of the total array area.
  • FIGS. 3 and 4 shows a small triangular grid section 40 of a transmitting face of an array, where the layout of the individual radiating elements in a triangular grid of columns and rows with each element occupying a hexagonal section of the total array area. (In FIGS. 3 and 4, only a 64 element sub-array 30, 40 of the total N-element array 22 is shown).
  • the choice of an element grid depends on packaging, thermal management and angular field-of-view considerations, and is well understood by those skilled in the art.
  • the directivity of the array aperture is defined as N times the directivity of a single array element 32 or 42, where N is the number of elements 32 or 42 and the single element directivity is 4pA ⁇ /l 2 .
  • the element area 34 or 44, A e is the area of one individual square 34 in FIG. 3 or one individual hexagon 44 in FIG. 4.
  • Lambda, I is the wavelength of the carrier frequency for which the array is designed (for example 20 GHz for a transmit array and 30 GHz for a receive array.
  • the angular width, at the -4 dB edge, of each of the beams formed by the array is approximately 67 ⁇ ID degrees and the contiguous beams will be spaced on 57 ⁇ ID degree centers. Since the transmission and reception are on different frequencies or wavelengths, the transmit and receive arrays must have different diameters in order that transmit/receive beam pairs have the same coverage.
  • FIG. 5 shows one of the individual transmitting elements
  • Radiating element 51 comprises passive radiator 52 which is coupled to a computer-controlled polarization network 53 located in active transmit module 54 that provides the ability to reconfigure beam polarization on-orbit.
  • Radiating element 51 and polarization network 53 are commercially available from various vendors and are well known to those skilled in the art.
  • Transmit module 54 comprises computer-controlled polarization switching network 53, isolator 56, monolithic microwave integrated circuit (MMIC) linear power amplifier 57, computer-controlled phase shifter 58 and computer- controlled attenuator 59.
  • polarization network 53 is coupled to isolator 56 which is in turn coupled to solid state power amplifier 57.
  • Amplifier 57 is coupled to active phase shifter 58 which is coupled to active attenuator 59.
  • Attenuator 59 is coupled to the RF input.
  • Phase shifter 58 and attenuator 59 are included to provide phase and amplitude control for compensation and calibration of each RF path through multi-beam phased array antenna.
  • a computer located elsewhere on the geosynchronous satellite sends commands to driver circuits within components of network 53, phase shifter 58 and attenuator 59 to cause changes in polarization, phase or attenuation as determined necessary by on-board monitoring equipment.
  • the components of active transmit module 54 are commercially available from Raytheon, Texas Instruments, et. al. and are well known to those skilled in the art.
  • FIG. 6 shows one of the individual receiving elements 60 of a receive phased array 29 which comprises receiving element 61 and active receive module 64.
  • Receiving element 61 includes passive radiator 62 which is coupled to a computer-controlled polarization network 63 located in active receive module 64 which provides on-orbit reconfiguration of beam polarization.
  • Receiving element 61 is commercially available from various vendors and is well known to those skilled in the art.
  • Receive module 64 comprises computer-controlled polarization switching network 63, Ii miter/protector circuit 66 to protect against high interfering signals, MMIC low-noise receiver amplifier 67, computer-controlled phase shifter 68 and computer-controlled attenuator 69.
  • polarization network 63 is coupled to limiter/protector circuit 66 which is coupled to low-noise solid state receiver amplifier 67.
  • Amplifier 67 is coupled to active phase shifter 68 which is coupled to active attenuator 69.
  • Attenuator 69 is coupled to RF Output.
  • Phase shifter 68 and attenuator 69 are included to provide phase and amplitude control for compensation and calibration of each RF path through multi- beam phased array antenna.
  • FIG. 7 shows a portion of one embodiment of multi-beam beamformer 26 or 27 (FIG. 2). As shown in FIG. 7, a portion of each beamformer 26 or 27 is a Butler matrix (which is well known to those skilled in the art) feed forming 8 beams with 8 radiating elements.
  • each Butler matrix beamformer 26 or 27 comprises a number of hybrid couplers 82 and fixed phase shifters 84.
  • the configuration of Butler matrix 70 shown in FIG. 8 is well known to those skilled in the art.
  • network 70 of FIG. 7 When network 70 of FIG. 7 is connected to each column of elements of an transmit phased array 28 or receive phased array 29 and a similar network is connected to each row of the column beam ports, pencil beams are formed.
  • the pencil beams are contiguous, touching each other at about the -4 dB points and, if transmit phased array 28 or receive phased array 29 was directed toward the earth, it would cover the portion of the earth as shown in FIG. 1.
  • a network 90 for combining a 64 element array of 8 columns and 8 rows is shown in FIG. 9. This network would form the 8 by 8 set of beams shown in FIG. 10.
  • FIG. 11 An alternative to the beamforming implementation which forms all the beams needed to cover the earth and then selects M of those beams for activation is an implementation in which only M beams are formed, but each is individually steerable to any position on the earth's surface.
  • the replacement for the beamforming network described in FIGS. 7, 8 and 9 is partially shown in FIG. 11.
  • the active modules (FIGS. 5 and 6) of each element of transmit phased array 28 or receive phased array 29 are each followed by a 1-to-M splitter/combiner network 100, where M is the number of beams to be implemented.
  • At each of the M outputs of splitter/combiner network 100 is computer-controlled phase shifter 102.
  • One of the M phase shifters 102 from each of the N array elements is then connected to an N-to-1 combiner/splitter to form an individually steerable beam.
  • MxN phase shifters are required in this implementation.
  • the microwave circuits are low power in nature and can be manufactured using very large scale integration techniques to minimize weight and cost.
  • the overall cost of the solid-state multi-beam phased array communications antenna with low- power transmitter power amplifiers distributed across the face of the antenna will be less than that of the traditional horn-fed reflector and high-power TWTA transmitter approach. Further, the described invention will have lower weight and provide on-orbit beam reconfigurability.
  • phased array 28 and 29 and Butler matrix 26 and 27 form a regular array of potential antenna beams that cover the entire hemispherical field of view of the satellite 20.
  • the switch matrix 24 and 25 selects which of these beams will be active at a particular time. In this way a single satellite design can be used for all orbit slot / coverage area locations and the disadvantages listed above are all avoided. Beams are switched and channels reallocated between beams whenever the service area for a satellite needs to change.
  • the phased-array on satellite 20 is more flexible than a horn-fed, dish antenna system.
  • the reconfigurability of system 20 provides a unique capability to dynamically allocate peaking capacity from GSO using multiple coverage of a service area from different slots.
  • one satellite covers region "A” and a second satellite covers region “B” from the same or a different slot.
  • a third satellite covers the busy parts of region “A” and the busy parts of region “B” from a different slot than the first two satellites.
  • This "peaking" satellite could very dynamically reconfigure to serve the peak areas while the other satellites provide the basic coverage.
  • the GSO phased array satellite system 20 has at least two more advantages.
  • the phased array approach allows smaller beams which in turn require less transmitter power. This power savings is used to compensate for the lower efficiency of the phased array and to allow a larger payload and or more beams to be included in the design if necessary.
  • the smaller beams also allow the earth terminal to use smaller antennas and lower transmitter power which enhances the commercial viability of the system. Accordingly, it is intended by the appended claims to cover all modifications of the invention which fall within the true spirit and scope of the invention.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Radio Relay Systems (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)

Abstract

Un système satellitaire géosynchrone, à antenne réseau à commande de phase à faisceaux multiples (20), émet vers la Terre des signaux à fréquence radioélectrique et en reçoit. Ce système satellitaire (20) possède des antennes réseau à commande de phase d'émission (28) et de réception (29), des formeurs de faisceaux (26 et 27), des matrices de commutation (24 et 25), une commande de commutation (23) et une charge utile de télécommunications (22). La couverture de faisceau du système satellitaire à antenne réseau à commande de phase (20) est reconfigurable lorsque le satellite se trouve sur son orbite géosynchrone. Ce système satellitaire géosynchrone, à antenne réseau à commande de phase à faisceaux multiples (20) constitue un moyen, peu onéreux et d'un bon compromis poids rendement, d'assurer des télécommunications dans le cas d'applications concernant des satellites géosynchrones.
PCT/US1997/012706 1996-07-18 1997-07-16 Systeme satellitaire geosynchrone de telecommunications a zone de desserte reconfigurable WO1998004017A1 (fr)

Applications Claiming Priority (2)

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US68348096A 1996-07-18 1996-07-18
US08/683,480 1996-07-18

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FR (1) FR2751494A1 (fr)
GB (1) GB2315644A (fr)
WO (1) WO1998004017A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001003310A1 (fr) * 1999-07-01 2001-01-11 Assuresat, Inc. Satellite de telecommunications de substitution universel
US20120017247A1 (en) * 2008-12-10 2012-01-19 Econet Wireless Ip Holdings Limited Content broadcasting

Families Citing this family (10)

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JPH10256974A (ja) * 1997-03-14 1998-09-25 Mitsubishi Electric Corp 移動体衛星通信システム
US6011512A (en) * 1998-02-25 2000-01-04 Space Systems/Loral, Inc. Thinned multiple beam phased array antenna
US6377558B1 (en) 1998-04-06 2002-04-23 Ericsson Inc. Multi-signal transmit array with low intermodulation
US6160519A (en) * 1998-08-21 2000-12-12 Raytheon Company Two-dimensionally steered antenna system
US6304225B1 (en) 1998-08-21 2001-10-16 Raytheon Company Lens system for antenna system
US6275184B1 (en) 1999-11-30 2001-08-14 Raytheon Company Multi-level system and method for steering an antenna
AU2001286513A1 (en) * 2000-08-16 2002-02-25 Raytheon Company Switched beam antenna architecture
CN104062930B (zh) * 2013-11-29 2017-05-10 中国空间技术研究院 一种通用化液晶屏触控式开关矩阵控制卡及其应用方法
FR3062267B1 (fr) * 2017-01-20 2020-10-02 Airbus Defence & Space Sas Architecture de charge utile d’un satellite de telecommunications
US11923924B2 (en) * 2018-02-26 2024-03-05 Parallel Wireless, Inc. Miniature antenna array with polar combining architecture

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EP0405372A1 (fr) * 1989-06-29 1991-01-02 Ball Corporation Réseau d'antenne à faisceaux multiples
US5434575A (en) * 1994-01-28 1995-07-18 California Microwave, Inc. Phased array antenna system using polarization phase shifting
WO1995028747A2 (fr) * 1994-04-18 1995-10-26 International Mobile Satellite Organization Systeme d'antennes
WO1996003814A1 (fr) * 1994-07-22 1996-02-08 International Mobile Satellite Organization Systeme de telecommunications mobile par satellite amrt multifaisceau
EP0786826A2 (fr) * 1996-01-29 1997-07-30 He Holdings, Inc. Dba Hughes Electronics Dispositif de communication à dispersion d'intermodulation

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FR2695775B1 (fr) * 1992-09-11 1994-11-10 France Telecom Procédé de reconfiguration de couvertures de faisceau d'antenne dans un réseau par satellite.

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EP0405372A1 (fr) * 1989-06-29 1991-01-02 Ball Corporation Réseau d'antenne à faisceaux multiples
US5434575A (en) * 1994-01-28 1995-07-18 California Microwave, Inc. Phased array antenna system using polarization phase shifting
WO1995028747A2 (fr) * 1994-04-18 1995-10-26 International Mobile Satellite Organization Systeme d'antennes
WO1996003814A1 (fr) * 1994-07-22 1996-02-08 International Mobile Satellite Organization Systeme de telecommunications mobile par satellite amrt multifaisceau
EP0786826A2 (fr) * 1996-01-29 1997-07-30 He Holdings, Inc. Dba Hughes Electronics Dispositif de communication à dispersion d'intermodulation

Cited By (3)

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Publication number Priority date Publication date Assignee Title
WO2001003310A1 (fr) * 1999-07-01 2001-01-11 Assuresat, Inc. Satellite de telecommunications de substitution universel
US6192217B1 (en) 1999-07-01 2001-02-20 Assuresat, Inc. Universal replacement communications satellite
US20120017247A1 (en) * 2008-12-10 2012-01-19 Econet Wireless Ip Holdings Limited Content broadcasting

Also Published As

Publication number Publication date
GB2315644A (en) 1998-02-04
FR2751494A1 (fr) 1998-01-23
JPH1079696A (ja) 1998-03-24
GB9713722D0 (en) 1997-09-03

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