Phased Array Antenna System

Abstract

A phased array antenna system capable of controlling the altitude and / or attitude of a plurality of element satellites with a simple configuration is provided. [Solution] The phased array antenna system of the present disclosure is an antenna system comprising a plurality of first element satellites each provided with a first antenna section, and a second element satellite, wherein the plurality of first element satellites and the second element satellites are arranged in an array, and each of the plurality of first element satellites is provided with a first spacing control means for controlling the spacing between it and another first element satellite or the second element satellite, and the second element satellite is provided with an altitude control means for controlling the altitude of the second element satellite and / or an attitude control means for controlling the attitude of the second element satellite, and a second spacing control means for controlling the spacing between it and at least some of the plurality of first element satellites.

Description

[Technical Field]

[0001] The present disclosure relates to phased array antenna systems. [Background technology]

[0002] It has been proposed to deploy a large number of small satellites in space, fly them in formation, and have these small satellites communicate wirelessly with each other, thereby functioning as a wire-free phased array antenna. For example, Patent Document 1 describes that a plurality of small satellites constitute a phased array antenna system, which relays communications between communication devices on the ground. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7416468 Summary of the Invention [Problem to be solved by the invention]

[0004] In such phased array antenna systems, it may be necessary to control the altitude and attitude of small satellites for various reasons, such as correcting deviations that occur during orbit, controlling communications, etc. However, the manufacturing costs of altitude and attitude control means are often high, and installing such control means may result in the satellite becoming larger.

[0005] Therefore, an object of the present invention is to provide a phased array antenna system that can control the altitude and / or attitude of a plurality of element satellites with a simple configuration. [Means for solving the problem]

[0006] The phased array antenna system of the present disclosure is an antenna system comprising a plurality of first element satellites each provided with a first antenna unit, and a second element satellite, wherein the first antenna units provided on the plurality of first element satellites constitute a phased array antenna, each of the plurality of first element satellites comprises a first spacing control means for controlling the spacing between it and another first element satellite or a second element satellite, and the second element satellite comprises an altitude control means for controlling the altitude of the second element satellite and / or an attitude control means for controlling the attitude of the second element satellite, and a second spacing control means for controlling the spacing between it and at least some of the plurality of first element satellites. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a phased array antenna system that is capable of controlling the altitude and / or attitude of a plurality of element satellites with a simple configuration. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a conceptual diagram for explaining an overview of a satellite communication system 1 according to the present embodiment. [Figure 2] FIG. 2 is a diagram for explaining a formation flight by the phased array antenna system 2 according to the present embodiment. [Figure 3] 1 is a schematic diagram showing at least a part of a phased array antenna system 2 according to this embodiment viewed from a direction perpendicular to a reference plane S. FIG. [Figure 4] 1 is a schematic diagram showing at least a part of a phased array antenna system 2 according to this embodiment viewed from a direction parallel to a reference plane S. FIG. [Figure 5] FIG. 1 is a schematic perspective view showing an example of the configuration of a first element satellite 10 according to the present embodiment. [Figure 6] 2 is a block diagram showing an example of the functional configuration of a first element satellite 10 according to the present embodiment. FIG. [Figure 7] FIG. 2 is a block diagram showing an example of the functional configuration of a second element satellite 20 according to the present embodiment. [Figure 8] FIG. 10 is a side view of a second element satellite 20 according to a first modified example, viewed from a direction perpendicular to the Z axis. [Figure 9] FIG. 10 is a plan view of a second element satellite 20 according to a first modified example, viewed from a direction parallel to the Z axis. [Figure 10] 10 is a block diagram showing an example of the functional configuration of a second element satellite 20 according to a first modified example. FIG. [Figure 11] FIG. 10 is a schematic diagram showing at least a part of a phased array antenna system 2 according to a second modification viewed from a direction parallel to a reference plane S. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present disclosure will be described with reference to the accompanying drawings. In this disclosure, for convenience, a Cartesian coordinate system consisting of an X-axis, a Y-axis, and a Z-axis may be attached to the drawings. In this case, directions parallel to the X-axis, Y-axis, and Z-axis are referred to as the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively. The plane defined by the X-axis and the Y-axis is referred to as the XY plane. For convenience, the positive direction of the Z-axis (the direction of the arrow) will be referred to as the sky side and up or upward, and the negative direction of the Z-axis (the direction opposite to the arrow) will be referred to as the ground side and down or downward.

[0010] (1) Overview of Satellite Communications System 1 1 is a conceptual diagram for explaining an overview of a satellite communication system 1 according to this embodiment. The satellite communication system 1 includes a phased array antenna system 2, a transmitter 3, and a receiver 4.

[0011] The phased array antenna system 2 includes a plurality of first element satellites 10 and at least one second element satellite 20. The phased array antenna system 2 is configured to be capable of performing formation flight, which will be described later, at an altitude of, for example, several hundred kilometers to several thousand kilometers. The plurality of first element satellites 10 and at least one second element satellite 20 are arranged in an array. The arrangement of the plurality of first element satellites 10 and at least one second element satellite 20 is not particularly limited, and may be, for example, a linear, planar, lattice, or concentric circular arrangement. In the present disclosure, the first element satellite 10 and the second element satellite 20 may be collectively referred to as "element satellites 100."

[0012] In this embodiment, a micro-element satellite is used as the first element satellite 10. For example, the size of one first element satellite 10 is several centimeters to several tens of centimeters. The total number N of first element satellites 10 constituting the phased array antenna system 2 is not particularly limited. The total number N of first element satellites 10 may be several hundred, several thousand, or tens of thousands or more. Furthermore, the second element satellite 20 may be a micro-element satellite similar to the first element satellite 10, or may be larger in size than the first element satellite 10.

[0013] In this embodiment, the distance between adjacent first element satellites 10 or between the first element satellite 10 and the second element satellite 20 may be, for example, several centimeters to several tens of centimeters. These distances may be approximately the wavelength of the radio waves transmitted and received by the phased array antenna system 2, or may be shorter than the wavelength (e.g., assumed frequency band = 0.8 GHz to 60 GHz).

[0014] The phased array antenna system 2 may receive a transmission signal transmitted from a transmitter 3. The phased array antenna system 2 may also transmit a transmission signal to a receiver 4. The phased array antenna system 2 may relay communication between the transmitter 3 and the receiver 4. That is, the phased array antenna system 2 may receive a transmission signal from the transmitter 3, generate a transmission signal based on the signal generated thereby, and transmit the transmission signal to the receiver 4.

[0015] The transmitter 3 and the receiver 4 are not particularly limited. For example, the transmitter 3 and the receiver 4 may be mobile stations such as smartphones. In this case, the plurality of first element satellites 10 of the phased array antenna system 2 may form a service link with the mobile stations (transmitters 3 and / or receivers 4). Also, for example, the transmitter 3 and the receiver 4 may be base stations. In this case, the second element satellite 20 of the phased array antenna system 2 may form a feeder link with the base station (transmitter 3 and / or receiver 4). The transmitter 3 and the receiver 4 may be provided together in one device.

[0016] (2) Formation Flight Fig. 2 is a diagram for explaining a formation flight by the phased array antenna system 2 according to this embodiment. Fig. 2 shows the phased array antenna system 2 according to this embodiment performing a formation flight with the Earth at its center. In the illustrated example, for convenience of explanation, of the multiple element satellites 10 provided in the phased array antenna system 2, only the first element satellite 10A, the first element satellite 10B, the first element satellite 10C, and the second element satellite 20 are shown.

[0017] The element satellites 100 (first element satellite 10 and second element satellite 20) included in the phased array antenna system 2 are configured to be capable of performing formation flight. That is, the element satellites 100 included in the phased array antenna system 2 are configured to be able to orbit the Earth along an orbit centered on the Earth that is unique to each element satellite 100, while maintaining their relative positional relationships with each other. As an example, Fig. 2 shows the orbits of each element satellite 100 centered on the Earth, namely, orbit OA of the first element satellite 10A, orbit OB of the first element satellite 10B, orbit OC of the first element satellite 10C, and orbit OP of the second element satellite 20.

[0018] The plurality of element satellites 100 (first element satellite 10 and second element satellite 20) provided in the phased array antenna system 2 are configured to be able to orbit in the above-mentioned formation flight in a manner that rotates while maintaining a relative positional relationship with each other on a record orbit centered on a reference point P within a virtual reference plane in which they orbit together with the plurality of first element satellites 10 and second element satellites 20. In other words, the element satellites 100 provided in the phased array antenna system 2 are configured to be able to orbit so as to rotate (spin on their own axes) around the reference point P at the same angular velocity during the formation flight.

[0019] The record disc orbit may be a concentric orbit centered on a reference point P within a virtual reference plane that orbits together with the element satellites 100 (first element satellite 10 and second element satellite 20), and may also be referred to as a GCO (General Circular Orbit). In the example of FIG. 2, one record disc orbit OR is shown as a circular orbit of a predetermined radius centered on the reference point P. In the example of FIG. 2, the position of the second element satellite 20 coincides with the reference point P. In the example of FIG. 2, the first element satellites 10A, 10B, and 10C are configured to be able to orbit around the reference point P (second element satellite 20) at the same angular velocity along the record disc orbit OR while maintaining their relative positional relationships with each other.

[0020] 2, the first element satellites 10A, 10B, and 10C all orbit along a single record disc orbit OR at the same distance (radius) from the reference point P (the second element satellite 20). However, the record disc orbit of any of the element satellites 100 (the first element satellite 10 and the second element satellite 20) included in the phased array antenna system 2 may have any distance (radius) from the reference point P as long as it is centered at the reference point P. In other words, each of the multiple element satellites 100 included in the phased array antenna system 2 may be configured to orbit in a manner rotating along one of multiple record disc orbits at different distances (radius) from the reference point P. Furthermore, in the phased array antenna system 2 according to this embodiment, as shown in FIG. 2, the element satellite 100 may be disposed at the position of the reference point P, or it is not necessarily required that the element satellite 100 be disposed at the position of the reference point P.

[0021] (3) Basic configuration (3-1) Arrangement of each element satellite 100 The arrangement of each element satellite 100 during a formation flight according to this embodiment will be described with reference to Figures 3 and 4. Figure 3 is a schematic diagram of at least a part of the phased array antenna system 2 according to this embodiment viewed from a direction perpendicular to a reference plane S (an example of the above-mentioned virtual reference plane). Figure 4 is a schematic diagram of at least a part of the phased array antenna system 2 according to this embodiment viewed from a direction parallel to the reference plane S. In Figures 3 and 4, the reference plane is a plane parallel to the XY plane.

[0022] 3, the plurality of element satellites 100 included in the phased array antenna system 2 according to this embodiment are arranged in an array on a reference plane S. The manner in which the plurality of element satellites 100 are arranged is not particularly limited, and may be, for example, a linear, planar, lattice, or concentric arrangement. The plurality of element satellites 100 are configured to be able to fly in a rotational manner while maintaining their relative positional relationships with each other on a record-like orbit centered on a reference point P within the reference plane S during formation flight.

[0023] In the example of FIG. 3, of the multiple element satellites 100, the second element satellite 20 is arranged at reference point P, and the multiple first element satellites 10 are arranged in a substantially lattice pattern around reference point P (second element satellite 20) on reference plane S. In the example of FIG. 3, the rotation direction of the multiple first element satellites 10 around reference point P (second element satellite 20) is counterclockwise as shown by the arrow. However, this is not limited thereto, and the rotation direction of the multiple first element satellites 10 may also be clockwise. Note that any of the first element satellites 10 may be arranged at reference point P instead of the second element satellite 20, or neither the first element satellite 10 nor the second element satellite 20 may be arranged.

[0024] (3-2) Functional configuration of the first satellite element 10 Fig. 5 is a schematic perspective view showing an example of the configuration of the first element satellite 10 according to this embodiment. Fig. 6 is a block diagram showing an example of the functional configuration of the first element satellite 10 according to this embodiment.

[0025] As shown in FIG. 6, the first element satellite 10 includes a control device 11, an adjustment mechanism 12, an antenna 13, an antenna 14, and a transmission / reception circuit 15.

[0026] The control device 11 is a device that controls the overall operation of the first element satellite 10. The control device 11 includes one or more processors 111 (hereinafter simply referred to as "processor 111") and one or more storage devices 112 (hereinafter simply referred to as "storage device 112"). The processor 111 includes a CPU (Central Processing Unit) and the like, and performs various types of information processing. The storage device 112 stores various types of information required for processing by the processor 111. The storage device 112 stores a control program. The control program is a computer program executed by the processor 111, and the functions of the control device 11 are realized by cooperation between the processor 111 and the storage device 112. The control program may be recorded on a computer-readable recording medium.

[0027] The adjustment mechanism 12 is a mechanism for adjusting the distance between the first element satellite 10 and the other element satellites 10 under the control of the control device 11. The adjustment mechanism 12 will be described in detail later.

[0028] The antenna 13 is an example of a first antenna unit, and receives radio waves (an example of a signal) transmitted from a transmission source (such as the transmitter 3) and outputs the radio waves to the transmission / reception circuit 15. The antenna 13 also outputs radio waves to an external device (such as the receiver 4) based on a signal generated by the transmission / reception circuit 15. As will be described later, the excitation weight of the antenna 13 may be controlled by signal processing in the transmission / reception circuit 15. Here, the excitation weight is a coefficient for adjusting the amplitude and / or phase of the excitation current (voltage) of the antenna element.

[0029] As shown in Fig. 5, the first element satellite 10 has a substantially cubic shape. As shown in Fig. 5, the antenna 13 may be provided on one surface of the first element satellite 10 on the ground side / Z-axis negative direction side.

[0030] 3, the antennas 13 of the multiple first element satellites 10 included in the phased array antenna system 2 are arranged along a plane 300 perpendicular to the Z axis. The multiple antennas 13 arranged along the plane 300 constitute a phased array antenna. The directivity of the phased array antenna is determined by the excitation weight of each antenna 113. The phased array antenna may constitute a service link for communication with a terrestrial mobile station (transmitter 3 and / or receiver 4) or the like.

[0031] The transmission / reception circuit 15 performs predetermined signal processing on a signal generated by receiving radio waves at the antenna 13. The transmission / reception circuit 15 also outputs the signal that has undergone the predetermined signal processing to the antenna 13, thereby causing the antenna 13 to output radio waves to the outside. The transmission / reception circuit 15 includes a receiving unit 151, a transmitting unit 152, and a signal processing unit 153.

[0032] The receiving unit 151 performs predetermined signal processing on the signal generated by the antenna 13 receiving external radio waves, and outputs the signal to the signal processing unit 153. The receiving unit 151 may be configured with, for example, a low-noise amplifier, and may amplify the output signal from the antenna 13.

[0033] The transmitting unit 152 is configured with a power amplifier and the like, amplifies the signal output from the signal processing unit 153, and outputs the amplified signal to the antenna 13, thereby causing the antenna 13 to output radio waves to the outside.

[0034] The signal processing unit 153 performs predetermined signal processing such as phase shifting, modulation, and demodulation on the signal supplied from the receiving unit 151. The signal processing unit 153 also performs predetermined signal processing and outputs the signal to the transmitting unit 152. The signal processing unit 153 may, for example, control the transmitting and receiving circuit 15 so as to compensate for phase differences in the signals received by the antenna 13 among the multiple first element satellites 10. The signal processing unit 153 may perform this control so as to compensate not only for phase differences caused by differences in the positions of the multiple first element satellites 10, but also for phase differences caused by variations in the individual first element satellites 10 (including information measured before the launch of the first element satellite 10, etc.).

[0035] The signal processing (amplification, phase shift, modulation, demodulation, etc.) performed by the transmission / reception circuit 15 (receiving unit 151, transmitting unit 152, signal processing unit 153, etc.) is controlled, for example, under the control of the control device 11, so that the excitation weight of the antenna 13 becomes a predetermined value. In this case, the control device 11 controls the transmission / reception circuit 15, for example, based on excitation weight control information, so that the excitation weight of the antenna 13 becomes a desired value. The excitation weight control information may be calculated to compensate for deviation from a predetermined reference value based on the position of the first element satellite 10 and variations of the first element satellite 10 as an individual (including information measured before the launch of the first element satellite 10, etc.). The excitation weight control information may be calculated by the control device 11 or may be obtained from another device (another first element satellite 10, a ground device, etc.).

[0036] (3-3) Functional configuration of the second satellite 20 FIG. 7 is a block diagram showing an example of the functional configuration of the second element satellite 20 according to this embodiment. As shown in FIG. 7, the second element satellite 20 includes a control device 21, an adjustment mechanism 22, an antenna 23, an antenna drive mechanism 24, and a transmission / reception circuit 25.

[0037] The control device 21 is a device that controls the overall operation of the second element satellite 20. The control device 21 includes two or more processors 211 (hereinafter simply referred to as "processors 211") and two or more storage devices 212 (hereinafter simply referred to as "storage devices 212"). The processor 211 includes a CPU (Central Processing Unit) and performs various types of information processing. The storage device 212 stores various types of information required for processing by the processor 211. The storage device 212 stores a control program. The control program is a computer program executed by the processor 211, and the functions of the control device 21 are realized by cooperation between the processor 211 and the storage device 212. The control program may be recorded on a computer-readable recording medium.

[0038] The adjustment mechanism 22 is a mechanism for adjusting the altitude, attitude, and distance between the second element satellite 20 and other element satellites 10 under the control of the control device 21. The adjustment mechanism 22 will be described in detail later.

[0039] The antenna 23 is an example of a second antenna unit, and receives radio waves (an example of a signal) transmitted from a transmission source (such as the transmitter 3) and outputs the radio waves to the transmission / reception circuit 25. The antenna 23 also outputs radio waves to an external device (such as the receiver 4) based on a signal generated by the transmission / reception circuit 25. As will be described later, the excitation weight of the antenna 23 may be controlled by signal processing by the transmission / reception circuit 25.

[0040] The antenna 23 may be configured to be able to form a feeder link for transmitting and / or receiving signals to and from a ground station (such as the transmitter 3 and the receiver 4). As shown in Fig. 4, the antenna 23 may be arranged on the ground station side with respect to a plane 300 on which the phased array antenna is configured by arranging the above-described multiple antennas 13. That is, the position of the antenna 23 in the Z-axis direction may be closer to the ground station than the position of the plane 300 in the Z-axis direction (the negative Z-axis side in the example of Fig. 4), or may be between the phased array antenna and the ground station.

[0041] The antenna driving mechanism 24 is a driving mechanism for controlling the physical orientation of the antenna 23 under the control of the control device 21. The configuration of the antenna driving mechanism 24 is not particularly limited, and may be configured using any actuator or the like. The antenna driving mechanism 24 may, for example, control the orientation of the antenna 23 in the direction of a ground station with which the second element satellite 20 will communicate (e.g., feeder link communication). The antenna 23 may form a phased array antenna together with multiple antennas 13. In this case, the antenna 23 may be arranged within a plane 300.

[0042] The transmission / reception circuit 25 performs predetermined signal processing on a signal generated by receiving radio waves at the antenna 23. The transmission / reception circuit 25 also outputs the signal that has undergone the predetermined signal processing to the antenna 23, thereby causing the antenna 23 to output radio waves to the outside. The transmission / reception circuit 25 includes a receiving unit 251, a transmitting unit 252, and a signal processing unit 253.

[0043] The receiving unit 251 performs predetermined signal processing on the signal generated by the antenna 23 receiving external radio waves, and outputs the signal to the signal processing unit 253. The receiving unit 251 may be configured with, for example, a low-noise amplifier, and may amplify the output signal from the antenna.

[0044] The transmitting unit 252 is configured with a power amplifier or the like, amplifies the signal output from the signal processing unit 253, and outputs the amplified signal to the antenna 23, thereby causing the antenna 23 to output radio waves to the outside.

[0045] The signal processing unit 253 performs predetermined signal processing such as phase shifting, modulation, and demodulation on the signal supplied from the receiving unit 251. Furthermore, the signal processing unit 253 performs predetermined signal processing and outputs the signal to the transmitting unit 252.

[0046] The signal processing (amplification, phase shift, modulation, demodulation, etc.) performed by the transmission / reception circuit 25 (receiving unit 251, transmitting unit 252, signal processing unit 253, etc.) is controlled, for example, under the control of the control device 21, so that the excitation weight of the antenna 23 becomes a predetermined value. In this case, the control device 21 controls the transmission / reception circuit 25, for example, based on excitation weight control information, so that the excitation weight of the antenna 23 becomes a desired value. The excitation weight control information may be calculated to compensate for deviation from a predetermined reference value based on the position of the second element satellite 20 and variations of the second element satellite 20 as an individual (including information measured before the launch of the second element satellite 20, etc.). The excitation weight control information may be calculated by the control device 21 or may be acquired from another device (the first element satellite 20, a ground device, etc.).

[0047] (4) Adjustment of the altitude and / or attitude of the phased array antenna system 2 Next, adjustment of the altitude and / or attitude of the phased array antenna system 2 according to this embodiment will be described.

[0048] (4-1) Spacing control of each element satellite 10 As shown in FIG. 6 , the adjustment mechanism 12 of the first element satellite 10 may include, for example, an electromagnet 121 (an example of a first electromagnet) as an example of a distance control means (first distance control means) for controlling the distance between the first element satellite 10 and another first element satellite 10 and / or a second element satellite 20. The electromagnet 121 includes, for example, a coil and is configured to generate a magnetic force by passing a current through the coil under the control of the control device 11. The magnetic force adjusts the relative positional relationship between the first element satellite 10 and a nearby first element satellite 10 and / or a second element satellite 20, and controls the phased array antenna system 2 to maintain a desired array shape (for example, a planar shape). Note that the adjustment mechanism 12 of the first element satellite 10 may include, as the distance control means (first distance control means), not only the electromagnet 121 but also other means for controlling the distance between the first element satellite 10 and another first element satellite 10 and / or a second element satellite 20.

[0049] As shown in FIG. 5, the first element satellite 10 may have a substantially cubic shape. For example, during formation of the phased array antenna system 2, as shown in FIG. 5, two faces constituting the substantially cubic shape of the first element satellite 10 may face a direction perpendicular to the Z-axis direction, and the remaining four faces may face any direction parallel to the Z-axis direction. In particular, during formation flight, the orientation of the first element satellite 10 may rotate around the Z-axis. As shown in FIG. 5, the first element satellite 10 may include four electromagnets 121 provided near each of the four faces parallel to the Z-axis direction. With this configuration, as shown in FIG. 3, the four electromagnets 121 included in each first element satellite 10 can be arranged to face adjacent other adjacent first element satellites 10 and / or second element satellites 20. The control device 11 provided in the first element satellite 10 may control the magnetic force of each of the four electromagnets 121 provided in the first element satellite 10 so that the distance between the first element satellite 10 and other adjacent element satellites 10 (the first element satellite 10 and the second element satellite 20) is within a predetermined range.

[0050] As shown in FIG. 7 , the adjustment mechanism 22 of the second element satellite 20 may include, for example, an electromagnet 223 (an example of a second electromagnet) as an example of a distance control means (second distance control means) for controlling the distance between the second element satellite 20 and another first element satellite 10. The electromagnet 223 includes, for example, a coil and is configured to be able to generate a magnetic force by passing a current through the coil under the control of the control device 21. The magnetic force can adjust the relative positional relationship with a nearby first element satellite 10 that also generates a magnetic force, and can be controlled to maintain a desired array shape (for example, a planar shape). Note that the adjustment mechanism 22 of the second element satellite 20 may include, as the distance control means (second distance control means), not only the electromagnet 223 but also other means for controlling the distance between the second element satellite 20 and another first element satellite 10.

[0051] 3 and 4, the second element satellite 20 has a substantially cylindrical shape centered on an axis 20a parallel to the Z-axis direction. The dimension of the second element satellite 20 in the Z-axis direction may be greater than the dimension of the first element satellite 10 in the Z-axis direction. That is, one end of the second element satellite 20 on the positive Z-axis side may be positioned further toward the positive Z-axis direction than one end of the first element satellite 10 on the positive Z-axis side. Also, one end of the second element satellite 20 on the negative Z-axis side may be positioned further toward the negative Z-axis direction than one end of the first element satellite 10 on the negative Z-axis side.

[0052] 3, the second element satellite 20 may include eight electromagnets 223 provided at approximately equal intervals around the axis 20a of the second element satellite 20 near the outer surface of the second element satellite 20. This allows the eight electromagnets 223 included in the second element satellite 20 to be arranged to face the adjacent first element satellite 10, as shown in FIG. 5. The control device 21 included in the second element satellite 20 controls the magnetic force of the electromagnets 223 included in the second element satellite 20 so that the distances of other adjacent element satellites 10 (the first element satellite 10 and the second element satellite 20) from the second element satellite 20 are within a predetermined range.

[0053] As described above, the phased array antenna system 2 according to this embodiment is capable of controlling the spacing between the plurality of element satellites 10 (the first element satellite 10 and the second element satellite 20). This facilitates control of the relative positional relationship between the plurality of element satellites 10 (the first element satellite 10 and the second element satellite 20), and, for example, makes it easy to maintain the plurality of element satellites 10 in a desired array shape, such as a planar shape. Furthermore, as shown in FIG. 4 , in the phased array antenna system 2 according to this embodiment, at least one of the first element satellite 10 or the second element satellite 20 may be equipped with an electromagnet (the electromagnet 121 or the electromagnet 223). The electromagnet 121 equipped in the first element satellite 10 and the electromagnet 223 equipped in the second element satellite 20 may be arranged on the same plane (a plane parallel to the XY plane in the illustrated example). This enables the phased array antenna system 2 to efficiently control the spacing between the plurality of element satellites 10 (the first element satellite 10 and the second element satellite 20).

[0054] The shape of the first element satellite 10 is not limited to the above-described approximately cubic shape, and may be any shape. The number and arrangement of the electromagnets 121 included in the first element satellite 10 are not limited to those described above, and the first element satellite 10 may be provided with any number of electromagnets 121 arranged at any location on the first element satellite 10. The shape of the second element satellite 20 is not limited to the above-described approximately cylindrical shape, and may be provided with any shape. The number and arrangement of the electromagnets 223 included in the second element satellite 20 are not limited to those described above, and the second element satellite 20 may be provided with any number of electromagnets 223 arranged at any location on the second element satellite 20.

[0055] (4-2) Advanced Control 7, the adjustment mechanism 22 of the second element satellite 20 may include, for example, a thruster 221 as an example of altitude control means for controlling the altitude of the second element satellite 20. The configuration of the thruster 221 is not particularly limited, but may be, for example, a mechanism for moving the second element satellite 20 in any direction (X-axis direction, Y-axis direction, and / or Z-axis direction) using an engine that ejects propellant (gas, plasma, etc.) in a predetermined ejection direction, an ion beam, or the like.

[0056] The thrusters 221 are preferably arranged at positions spaced apart from the plane 300 on which the phased array antenna is configured with respect to the Z axis. Furthermore, the thrusters 221 are more preferably arranged on the positive Z axis side of the plane 300. In the example shown in FIGS. 3 and 4, the second element satellite 20 includes four thrusters 221 arranged at approximately equal intervals around the axis 20a near the end on the positive Z axis side, with their jet directions facing radially relative to the axis 20a. The number of thrusters 221 is not limited to four, and may be any number. Furthermore, the arrangement of the thrusters 221 does not need to be approximately equal, and they may be arranged at any position relative to the axis 20a.

[0057] As described in (4-1) above, in the phased array antenna system 2 according to this embodiment, it is easy to control the relative positional relationship between the multiple element satellites 100 (the first element satellite 10 and the second element satellite 20). Furthermore, it is possible to control the altitude of the entire phased array antenna system 2 by using altitude control means such as the thrusters 221 provided in the second element satellite 20. This eliminates the need to install expensive mechanisms such as the thrusters 221 on each of the first element satellites 10, thereby reducing the manufacturing cost of the entire phased array antenna system 2. Furthermore, it is possible to keep the size of the first element satellite 10 small, increasing the degree of freedom in the design of the phased array antenna system 2.

[0058] (4-3) Posture control The adjustment mechanism 22 of the second element satellite 20 may include, for example, a magnetic torquer 222 as an example of an attitude control means for controlling the attitude of the second element satellite 20. The magnetic torquer 222 is a mechanism that includes, for example, a coil and can generate torque by passing a current through the coil to interact with an external magnetic field such as that of the Earth. This makes it possible to rotate the attitude of the second element satellite 20 and adjust it to a desired orientation.

[0059] The attitude control means for controlling the attitude of the second element satellite 20 is not limited to the magnetic torquer 222, but may be, for example, a reaction wheel. A reaction wheel is a device that controls the attitude of a spacecraft by changing angular momentum using, for example, a disk rotated by an electric motor. By changing the rotational speed of the wheel, the orientation of the spacecraft body is adjusted by a reaction.

[0060] As described in (4-1) above, in the phased array antenna system 2 according to this embodiment, it is easy to control the relative positional relationship between the multiple element satellites 100 (the first element satellite 10 and the second element satellite 20). Then, it becomes possible to control the attitude of the entire phased array antenna system 2 by using attitude control means such as the magnetic torquer 222 provided in the second element satellite 20. In particular, it becomes unnecessary to mount expensive mechanisms such as the magnetic torquer 222 on each first element satellite 10, and it is possible to reduce the manufacturing cost of the entire phased array antenna system 2. Furthermore, it is possible to keep the size of the first element satellite 10 small, which increases the degree of freedom in the design of the phased array antenna system 2.

[0061] (5) Variations (5-1) First Modification Fig. 8 is a side view of the second element satellite 20 according to the first modified example when viewed from a direction perpendicular to the Z axis. Fig. 9 is a plan view of the second element satellite 20 according to the first modified example when viewed from a direction parallel to the Z axis. Fig. 10 is a block diagram showing an example of the functional configuration of the second element satellite 20 according to the first modified example.

[0062] As shown in FIG. 10 , the second element satellite 20 according to the first modification includes an electromagnet rotation mechanism 26. The electromagnet rotation mechanism 26 includes, for example, a bearing, a motor, a rotation shaft, and a drive control circuit. However, the configuration of the electromagnet rotation mechanism 26 is not limited to this, and other mechanisms may be adopted depending on the purpose. The multiple electromagnets 223 (four in number) may be rotatable around the axis 20a of the second element satellite 20 by control of the electromagnet rotation mechanism 26. The center of rotation is around the Z axis along the axis 20a of the two-element satellite 20, and the rotation of each electromagnet 223 may be adjusted to optimize magnetic interaction with the adjacent first element satellite 10.

[0063] As shown in Figures 8 and 9, the second element satellite 20 of the first modified example may be provided with four electromagnets 223 arranged at approximately equal intervals around the axis 20a of the second element satellite 20 near the outer surface of the electromagnet rotation mechanism 26 of the second element satellite 20.

[0064] The electromagnet rotation mechanism 26 can rotate the electromagnet 223 at a predetermined angular velocity (an example of a second angular velocity) under the control of, for example, the control device 21. Here, the predetermined angular velocity may be a velocity based on the angular velocity of rotation of the phased array antenna system 2 along the record orbit (an example of a first angular velocity). Specifically, for example, it may be the angular velocity of rotation of the record orbit itself, or an angular velocity to which another shift amount is added. The shift amount may be set arbitrarily, and may be set, for example, based on the number of element satellites 100 included in the phased array antenna system 2, the flight speed (formation flight) of the phased array antenna system 2, etc.

[0065] In the second element satellite 20 according to the first modification, the electromagnet 223 can be rotated by the electromagnet rotation mechanism 26, and thus the magnetic force of the electromagnet 223 can be efficiently exerted on the surrounding first element satellites 10 by facing the electromagnet 223 in a desired direction. This makes it possible to reduce the number of electromagnets 223 included in the second element satellite 20. As a result, it is possible to reduce the manufacturing cost of the phased array antenna system 2. Furthermore, particularly when the angular velocity of the rotation of the electromagnet 223 by the electromagnet rotation mechanism 26 matches the angular velocity of the rotation of the phased array antenna system 2 along the record orbit, the first element satellite 10 (the electromagnet 121 included therein) that faces the electromagnet 223 included in the second element satellite 20 is fixed, which can further enhance the effect of efficient spacing control between the element satellites 10.

[0066] The number and arrangement of the electromagnets 223 provided in the second element satellite 20 according to the first modified example are not limited to those described above, and the second element satellite 20 may have any number of electromagnets 223 arranged at any location in the electromagnet rotation mechanism 26.

[0067] (5-2) Second Modification Fig. 11 is a schematic diagram of at least a part of a phased array antenna system 2 according to the second modification, viewed from a direction parallel to a reference plane S. In Fig. 11, the reference plane is a plane parallel to the XY plane. Fig. 11 also shows an axis Zp that is parallel to the Z axis and passes through a reference point as the center of the record track.

[0068] 11 , in the phased array antenna system 2 according to the second modification, the second element satellite 20 does not have to be placed at the reference point P. The second element satellite 20 according to the second modification may be placed a predetermined distance away from the reference point P. In the example of FIG. 11 , the second element satellite 20 is placed at the end of the multiple element satellites 10 included in the phased array antenna system 2. Note that in FIG. 11 , one first element satellite 10 is placed at the reference point P.

[0069] In FIG. 11, the firing direction of the thruster 221 included in the second element satellite 20 according to the second modification does not face the other element satellites 10 (first element satellite 10). For example, the attitude control means (magnetic torquer 222, etc.) included in the second element satellite 20 may control the attitude of the second element satellite 20 so that the firing direction of the thruster 221 faces in a direction that does not face the other element satellites 10. Furthermore, the thruster 221 may control the altitude of the second element satellite 20 (such as by firing propellant) when the other element satellites 10 are not arranged in the firing direction of the thruster 221. On the other hand, the thruster 221 may stop controlling the altitude of the second element satellite 20 when the other element satellites 10 are arranged in the firing direction of the thruster 221. This makes it possible to protect the other element satellites 10 from the propellant fired from the thruster 221, the heat of the firing, etc.

[0070] (Appendix 1) An antenna system comprising a plurality of first element satellites each having a first antenna unit and a second element satellite, the first antenna units provided on the plurality of first element satellites constitute a phased array antenna; each of the plurality of first element satellites includes first distance control means for controlling a distance between the first element satellite and another first element satellite or the second element satellite; The second element satellite is altitude control means for controlling the altitude of the second element satellite and / or attitude control means for controlling the attitude of the second element satellite; and second distance control means for controlling distances to at least some of the first element satellites among the plurality of first element satellites. Antenna system. (Appendix 2) the second element satellite further comprises a second antenna unit, 2. The antenna system of claim 1, wherein the second antenna section is configured to be able to form a feeder link. (Appendix 3) The antenna system of claim 2, wherein the second antenna unit is positioned closer to a device that transmits and / or receives signals with the second antenna unit than the phased array antenna. (Appendix 4) The antenna system described in Appendix 2, wherein the second element satellite further includes a drive mechanism for controlling the orientation of the second antenna unit. (Appendix 5) 2. The antenna system of claim 1, wherein the altitude control means includes a thruster. (Appendix 6) 2. The antenna system of claim 1, wherein the attitude control means includes at least one of a magnetic torquer and a reaction wheel. (Appendix 7) the first gap control means includes a first electromagnet, 2. The antenna system of claim 1, wherein the second spacing control means includes a second electromagnet. (Appendix 8) 8. The antenna system of claim 7, wherein the second electromagnet is configured to be rotatable around the second element satellite. (Appendix 9) the plurality of first element satellites are configured to rotate at a first angular velocity on a record orbit centered on the second element satellite; The antenna system of claim 8, wherein the second electromagnet is configured to be rotatable around the second element satellite at a second angular velocity based on the first angular velocity. (Appendix 10) 8. The antenna system of claim 7, wherein the first electromagnets included in the plurality of first element satellites and the second electromagnets included in the second element satellite are arranged on the same plane. (Appendix 11) 6. The antenna system of claim 5, wherein the thruster is configured to perform a thrust when the plurality of first element satellites do not face the thrust direction of the thruster. (Appendix 12) a second element satellite constituting an antenna system including a plurality of first element satellites each provided with a first antenna unit and a second element satellite, the first antenna units provided on the plurality of first element satellites constitute a phased array antenna; each of the plurality of first element satellites includes first distance control means for controlling distances between the first element satellites and other first element satellites; The second element satellite is altitude control means for controlling the altitude of the second element satellite and / or attitude control means for controlling the attitude of the second element satellite; and second distance control means for controlling distances to at least some of the first element satellites among the plurality of first element satellites. Second element satellite.

[0071] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those illustrated and can be modified as appropriate. Furthermore, configurations shown in different embodiments can be partially substituted or combined with each other. [Explanation of symbols]

[0072] 1...satellite communications system, 2...phased array antenna system, 3...transmitter, 4...receiver, 10...first element satellite, 10A, 10B, 10C...first element satellite, 11...controller, 12...adjustment mechanism, 13...antenna, 14...antenna, 15...transmitter / receiver circuit, 20...second element satellite, 21...controller, 22...adjustment mechanism, 23...antenna, 24...antenna drive mechanism, 25...transmitter / receiver circuit, 26...electromagnet rotation mechanism, 121...electromagnet, 223...electromagnet, 221...thruster, 222...magnetic torquer, OA, OB, OC, OP...orbit, P...reference point, S...reference plane, T...rotation period, θ...separation angle

Claims

1. An antenna system comprising a plurality of first element satellites each provided with a first antenna unit, and a second element satellite, the first antenna units provided on the plurality of first element satellites constitute a phased array antenna; each of the plurality of first element satellites includes first distance control means for controlling a distance between the first element satellite and another first element satellite or the second element satellite; The second element satellite altitude control means for controlling the altitude of the second element satellite and / or attitude control means for controlling the attitude of the second element satellite; a second distance control means for controlling distances to at least some of the first element satellites among the plurality of first element satellites, the first spacing control means provided in the first element satellites and the second spacing control means provided in the second element satellite control the first element satellites and the second element satellite to maintain an array shape; Antenna system.

2. the second element satellite further comprises a second antenna unit; The antenna system according to claim 1 , wherein the second antenna section is configured to be able to form a feeder link.

3. The antenna system according to claim 2 , wherein the second antenna section is arranged closer to a device that transmits and / or receives signals with the second antenna section than the phased array antenna.

4. The antenna system according to claim 2 , wherein the second element satellite further comprises a drive mechanism for controlling the orientation of the second antenna portion.

5. 10. The antenna system of claim 1, wherein said altitude control means includes a thruster.

6. 2. The antenna system according to claim 1, wherein said attitude control means includes at least one of a magnetic torquer and a reaction wheel.

7. the first gap control means includes a first electromagnet, 2. The antenna system of claim 1, wherein said second spacing control means includes a second electromagnet.

8. The antenna system according to claim 7 , wherein the second electromagnet is configured to be rotatable about the second element satellite.

9. the plurality of first element satellites are configured to rotate at a first angular velocity on a record orbit centered on the second element satellite; 9. The antenna system according to claim 8, wherein the second electromagnet is configured to be rotatable about the second element satellite at a second angular velocity based on the first angular velocity.

10. 8. The antenna system according to claim 7, wherein the first electromagnets included in the plurality of first element satellites and the second electromagnets included in the second element satellites are arranged on the same plane.

11. 6. The antenna system of claim 5, wherein the thrusters are configured to perform a burn when the plurality of first element satellites are not facing a direction of burn of the thrusters.

12. a second element satellite constituting an antenna system including a plurality of first element satellites each provided with a first antenna unit and a second element satellite, the first antenna units provided on the plurality of first element satellites constitute a phased array antenna; each of the plurality of first element satellites includes first distance control means for controlling a distance between the first element satellite and another first element satellite; The second element satellite altitude control means for controlling the altitude of the second element satellite and / or attitude control means for controlling the attitude of the second element satellite; a second distance control means for controlling distances to at least some of the first element satellites among the plurality of first element satellites, the first spacing control means provided in the first element satellites and the second spacing control means provided in the second element satellite control the first element satellites and the second element satellite to maintain an array shape; Second element satellite.

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