Antenna for multipath satellite communication links
First Claim
1. An antenna system for coupling a terminal to a plurality of satellites of a constellation of low earth orbit satellites, each of the plurality of satellites being oriented, at any given time when in view of the terminal, at a particular elevation angle, comprising:
- a first sub-structure having a major plane that is oriented at a first angle with respect to an axis that is perpendicular to the surface of the earth;
a plurality N of second sub-structures individual ones of which have a local major plane that is disposed at a second angle to said major plane of said first sub-structure, each of said plurality N of sub-structures having an outwardly pointing normal from said local major plane that is oriented at a third angle around said axis from an outwardly pointing normal of an adjacent one of said sub-structures, said outwardly pointing normal of each of said plurality N of sub-structures being disposed so as to point away from said axis; and
at least one antenna element supported by said first sub-structure and by each of said plurality N of second sub-structures, wherein antenna elements of said first sub-structure and at least some of said plurality N of second sub-structures enable a spread spectrum communication between said terminal and at least one low earth orbit satellite over a range of elevation angles of said low earth orbit satellite.
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Accused Products
Abstract
An antenna (70) includes a first sub-structure (72) having a major plane that is oriented at a first angle (for example, 90°) with respect to an axis (normal) that is perpendicular to the surface of the earth. The antenna also includes a plurality (for example six) of second sub-structures (74) individual ones of which have a local major plane that is disposed at a second angle (for example, 45°) to the major plane of the first sub-structure. Each of the plurality of sub-structures have an outwardly pointing normal from the local major plane that is oriented at a third angle (for example, 60°) around the axis from an outwardly pointing normal of an adjacent one of the sub-structures. The outwardly pointing normal of each of the plurality of sub-structures is disposed so as to point away from the axis. At least one antenna element (76) is supported by the first sub-structure and by each of the plurality of second sub-structures. Antenna elements of the first sub-structure and at least some of the plurality of second sub-structures enable a spread spectrum communication between a terminal (13) and at least one low earth orbit satellite (12) over a range of elevation angles of the low earth orbit satellite.
121 Citations
35 Claims
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1. An antenna system for coupling a terminal to a plurality of satellites of a constellation of low earth orbit satellites, each of the plurality of satellites being oriented, at any given time when in view of the terminal, at a particular elevation angle, comprising:
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a first sub-structure having a major plane that is oriented at a first angle with respect to an axis that is perpendicular to the surface of the earth; a plurality N of second sub-structures individual ones of which have a local major plane that is disposed at a second angle to said major plane of said first sub-structure, each of said plurality N of sub-structures having an outwardly pointing normal from said local major plane that is oriented at a third angle around said axis from an outwardly pointing normal of an adjacent one of said sub-structures, said outwardly pointing normal of each of said plurality N of sub-structures being disposed so as to point away from said axis; and at least one antenna element supported by said first sub-structure and by each of said plurality N of second sub-structures, wherein antenna elements of said first sub-structure and at least some of said plurality N of second sub-structures enable a spread spectrum communication between said terminal and at least one low earth orbit satellite over a range of elevation angles of said low earth orbit satellite. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A communication system, comprising:
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a constellation of low earth orbit satellites individual ones of which each comprise means for receiving at least one communication feeder link from at least one ground station and means for transmitting the received at least one communication feeder as a downlink transmission to a plurality of terrestrially located terminals; and at least one ground station including means for transmitting said at least one communication feeder link to at least one of said satellites and further comprising means for coupling said at least one feeder link to a terrestrially located communications system;
whereineach of the plurality of satellites is oriented, at any given time when in view of one of said terminals, at a particular elevation angle; characterized in that said terminal comprises, an antenna that is comprised of a first sub-structure having a major plane that is oriented at a first angle with respect to an axis that is perpendicular to the surface of the earth;
a plurality N of second sub-structures individual ones of which have a local major plane that is disposed at a second angle to said major plane of said first sub-structure, each of said plurality N of sub-structures having an outwardly pointing normal from said local major plane that is oriented at a third angle around said axis from an outwardly pointing normal of an adjacent one of said sub-structures, said outwardly pointing normal of each of said plurality N of sub-structures being disposed so as to point away from said axis; and
at least one antenna element supported by said first sub-structure and by each of said plurality N of second sub-structures, wherein antenna elements of said first sub-structure and at least some of said plurality N of second sub-structures enable a spread spectrum communication to occur between said terminal and at least one low earth orbit satellite over a range of elevation angles of said low earth orbit satellite. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. A method for operating a terminal to receive a communication from at least one satellite of a plurality of low earth orbit satellites, each of the plurality of satellites being oriented, at any given time when in view of the terminal, at a particular elevation angle and at a particular azimuth angle, comprising the steps of:
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for a first range of elevation angles and azimuth angles, selecting a first portion of an antenna structure to receive the communication, the first portion being disposed at a first angle with respect to an axis that is normal to the surface of the earth; for a second range of elevation angles and azimuth angles, selecting a second portion of the antenna structure to receive the communication, the second portion being disposed at a second angle with respect to the axis that is normal to the surface of the earth. - View Dependent Claims (21, 22, 23, 24, 25, 26)
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27. A method for operating a terminal to transmit a communication to at least one satellite of a plurality of low earth orbit satellites, each of the plurality of satellites being oriented, at any given time when in view of the terminal, at a particular elevation angle and at a particular azimuth angle, comprising the steps of:
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for a first range of elevation angles and azimuth angles, selecting a first portion of an antenna structure to transmit the communication, the first portion being disposed at a first angle with respect to an axis that is normal to the surface of the earth; and for a second range of elevation angles and azimuth angles, selecting a second portion of the antenna structure to transmit the communication, the second portion being disposed at a second angle with respect to the axis that is normal to the surface of the earth. - View Dependent Claims (28, 29, 30, 31)
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32. A method for operating a terminal to receive a communication from at least one satellite of a plurality of low earth orbit satellites, each of the plurality of satellites being oriented, at any given time when in view of the terminal, at a particular elevation angle and at a particular azimuth angle, comprising the steps of:
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for a first predicted range of elevation angles and azimuth angles of the at least one satellite, selecting a first portion of an antenna structure to receive the communication, the first portion being disposed at a first angle with respect to an axis that is normal to the surface of the earth; and for a second predicted range of elevation angles and azimuth angles of the at least one satellite, selecting a second portion of the antenna structure to receive the communication, the second portion being disposed at a second angle with respect to the axis that is normal to the surface of the earth. - View Dependent Claims (33)
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34. A method for operating a terminal to receive a communication from at least one satellite of a plurality of low earth orbit satellites, each of the plurality of satellites being oriented, at any given time when in view of the terminal, at a particular elevation angle and at a particular azimuth angle, comprising the steps of:
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measuring a signal strength of a signal received from the at least one satellite with at least one of a plurality of antennas individual ones of which are oriented to receive a satellite transmission from a satellite disposed within a range of elevation angles and azimuth angles, wherein certain ones of the ranges of elevation angles and azimuth angles overlap one another; for a first range of elevation angles and azimuth angles of the at least one satellite wherein the measured signal strength exceeds a predetermined threshold value, selecting a first antenna to receive the communication, the first antenna being oriented at a first angle with respect to an axis that is normal to the surface of the earth; and for a second range of elevation angles and azimuth angles of the at least one satellite wherein the measured signal strength exceeds the predetermined threshold value, selecting a second antenna to receive the communication, the second antenna being oriented at a second angle with respect to the axis that is normal to the surface of the earth. - View Dependent Claims (35)
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Specification