Antenna equipment for artificial satellites

Abstract

For example, the present invention provides a novel and improved antenna device for artificial satellites that can suppress deformation of the antenna device and changes in the relative positions of multiple conductive parts with a simpler configuration. [Solution] In the extended state of the antenna member, the antenna member comprises at least one antenna element formed in the shape of a thin plate, a plurality of conductor portions which are part of the antenna element and which extend in a strip shape in the extension direction of the antenna member in the extended state and are spaced apart in the width direction of the antenna member, and a thin film-like holding member which is stretched between the plurality of conductor portions in a state that partially overlaps the plurality of conductor portions in the thickness direction of the antenna member, and maintains the spacing between the plurality of conductor portions while maintaining the insulating state between the plurality of conductor portions.

Description

Technical Field

[0001] The present invention relates to an antenna device for a satellite.

Background Art

[0002] Conventionally, an antenna device for a satellite deployed in space has been known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In this type of satellite, if deformation occurs in the conductor part after the antenna device is deployed, or if a change in the relative position occurs between the plurality of conductor parts when the antenna device has a plurality of conductor parts, the electrical characteristics of the antenna may change, which is not preferable.

[0005] Therefore, one of the objectives of the present invention is to provide a novel and improved antenna device for a satellite and a satellite that can suppress bending deformation of the antenna device and changes in the relative positions of a plurality of conductor parts with a simpler configuration, for example.

Means for Solving the Problems

[0006] The present invention relates to an antenna device for an artificial satellite, which includes, for example, an antenna member having a substantially strip-like shape and being used in an extended state where the winding state, which is wound in the longitudinal direction, is released and the antenna member is elastically extended in a strip shape, wherein in the extended state, the antenna member comprises at least one antenna element formed in the shape of a thin plate, a plurality of conductor portions which are each part of the antenna element and extend in a strip shape in the direction of extension of the antenna member in the extended state and are spaced apart in the width direction of the antenna member, and a thin film-like holding member which is spanned between the plurality of conductor portions at positions where the plurality of conductor portions face each other, and which maintains an insulating state between the plurality of conductor portions while suppressing changes in the relative positions of the plurality of conductor portions.

[0007] In the aforementioned antenna device for the artificial satellite, the operating frequencies of the multiple conductive parts may be different.

[0008] The antenna device for the artificial satellite includes a support member that cantilever-supports the antenna member in the extended state, and the antenna element is a folded antenna element having a first portion that extends in a strip shape away from the support member in the extended state, a folded portion that extends in the width direction of the antenna member at the tip of the first portion, and a second portion that extends in a strip shape from the folded portion toward the support member to a position away from the support member at a position spaced apart from the first portion in the width direction of the antenna member, and the plurality of conductive portions may be a part of the first portion and the second portion.

[0009] In the aforementioned antenna device for artificial satellites, the holding member may be spanned between the first portion and at least the portion of the second portion that is further away from the folded portion than the longitudinal middle portion of the second portion.

[0010] In the aforementioned antenna device for the artificial satellite, the plurality of conductive portions include a third portion which is part of a linear antenna element extending in a strip shape from the support member, separate from the folded antenna element, and the holding member may be spanned between the first portion, the second portion, and the third portion.

[0011] In the aforementioned antenna device for the artificial satellite, the operating frequency of the folded antenna element may be lower than the operating frequency of the linear antenna element.

[0012] In the aforementioned antenna device for artificial satellites, the cross-section of the antenna member intersecting the longitudinal direction may be curved convexly in the thickness direction of the antenna member, at least at the base portion of the antenna member supported by the support member. [Effects of the Invention]

[0013] According to the present invention, for example, it is possible to provide a novel and improved antenna device for artificial satellites that can suppress deformation of the antenna device and changes in the relative positions of multiple conductive parts with a simpler configuration. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is an exemplary and schematic perspective view of the antenna device of the embodiment in its deployed state. [Figure 2] Figure 2 is an exemplary and schematic side view (partially a cross-sectional view) showing the housing of the subassembly included in the antenna device of the embodiment within the housing. [Figure 3] Figure 3 is an exemplary and schematic plan view (partially a cross-sectional view) showing the housing of the subassemblies included in the antenna device of the embodiment within the housing. [Figure 4] Figure 4 is an illustrative and schematic side view (partially a cross-sectional view) showing the protrusion of a subassembly included in the antenna device of the embodiment from the housing. [Figure 5]FIG. 5 is an exemplary and schematic perspective view showing a part of the antenna device according to the embodiment. [Figure 6] FIG. 6 is an exemplary and schematic plan view of the antenna member according to the embodiment. [Figure 7] FIG. 7 is an exemplary and schematic plan view of the antenna member according to the first modification of the embodiment. [Figure 8] FIG. 8 is an exemplary and schematic plan view of the antenna member according to the second modification of the embodiment. [Figure 9] FIG. 9 is an exemplary and schematic plan view of the antenna member according to the third modification of the embodiment. [Figure 10] FIG. 10 is an exemplary and schematic plan view of the antenna member according to the fourth modification of the embodiment.

MODE FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, exemplary embodiments and modifications of the present invention will be disclosed. The configurations of the embodiments and modifications shown below, as well as the actions and results (effects) brought about by the configurations, are examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments and modifications. Further, according to the present invention, it is possible to obtain at least one of various effects (including derivative effects) obtained by the configuration.

[0016] The inventions according to a plurality of embodiments and modifications disclosed below have the same components, and the same components exhibit the same actions and effects. Hereinafter, the same components will be given common reference numerals, and redundant descriptions may be omitted.

[0017] In this specification, ordinal numbers are given for convenience of distinguishing components, directions, etc., and do not indicate priority or order, nor limit the number.

[0018] Also, the X direction, Y direction, and Z direction shown in each figure intersect and are substantially orthogonal to each other.

[0019] [Embodiment] [Antenna Device] FIG. 1 is a perspective view of an antenna device 100 provided in a part of a satellite 1 according to an embodiment in a deployed state. The antenna device 100 is used in the deployed state in outer space.

[0020] As shown in FIG. 1, the antenna device 100 includes a housing 200 and a sub-assembly 300. The sub-assembly 300 includes a support member 311 and one or more antenna members 320. In the present embodiment, as an example, the antenna device 100 includes four antenna members 320 (320-1 to 320-4). These four antenna members 320 all have substantially the same structure and extend substantially along the radial direction with respect to the axis Ax at 90° intervals around the axis Ax extending in the Z direction. Each antenna member 320 has a conductor member 321A as an antenna element. In this arrangement and configuration, by appropriately controlling the power supply to each conductor member 321A, the antenna device 100 can radiate circularly polarized waves. The antenna members 320-1 to 320-4 are an example of a first antenna member.

[0021] [Housing and Sub-assembly] FIG. 2 is a side view of the antenna device 100 showing a housed state in which the sub-assembly 300 is housed in the housing 200.

[0022] As shown in FIG. 2, the housing 200 has a bottomed cylindrical shape that is open in the Z direction. The housing 200 has a bottom wall 200a and a peripheral wall 200b. The bottom wall 200a is located at an end in the opposite direction of the Z direction, intersects and extends orthogonally to the Z direction. The peripheral wall 200b extends in the Z direction from the bottom wall 200a. The inner surface 200c of the peripheral wall 200b is formed in a cylindrical inner surface shape centered on the axis Ax. The housing 200 is made of, for example, an aluminum-based material.

[0023] In the deployed state, the support member 311 included in the subassembly 300 cantilever supports the radially inward end of each strip-shaped antenna member 320, as shown in Figure 1. The support member 311 is made of, for example, an aluminum-based material.

[0024] As shown in Figure 1, the antenna member 320 has a roughly strip-like shape, and in the unfolded state, both ends in the width direction are aligned in the Z direction, and the longitudinal direction is facing radially outward from the axis Ax, and it is supported (fixed) to the support member 311. In this unfolded state, the thickness direction of the antenna member 320 is roughly aligned with the circumferential direction of the axis Ax. In this unfolded state, each antenna member 320 can be said to be in an extended state.

[0025] As shown in Figure 1, the antenna members 320 supported by the support member 311 can be bent to substantially follow the circumferential direction around axis Ax and wound in the longitudinal direction. Figure 3 is a plan view of the antenna device 100 showing the housing state in which the subassembly 300 is housed within the housing 200. In the housing state shown in Figures 2 and 3, the antenna members 320 are elastically bent in the longitudinal direction and are wound around the support member 311 in a spiral shape, clockwise when viewed in the opposite direction of the Z direction (hereinafter simply referred to as a plan view). This wound state is maintained by the constraint (restraint) of the inner surface 200c of the housing 200. That is, because the antenna members 320 are elastically bent, when this constraint is released, they extend elastically to a state where they are substantially straight in the longitudinal direction, as shown in Figure 1.

[0026] Furthermore, as can be seen from Figure 1, in the unfolded (extended) state, each antenna member 320 is curved in the width direction such that it is convex in one direction in the thickness direction. In other words, the cross section of the antenna member 320 intersecting the extension direction is curved such that it is convex in one direction in the thickness direction. As a result, the bending rigidity of the antenna member 320 in the thickness direction is increased, and the elastic restoring force from the wound state to the extended state is increased accordingly. It is sufficient for at least the base portion of the antenna member 320 to be curved in the width direction, but it is more preferable that the entire longitudinal portion of the antenna member 320 is curved in the width direction, as in this embodiment.

[0027] In this case, the antenna member 320, which is curved in the width direction so as to be convex in one direction in the thickness direction, has high bending rigidity in the longitudinal direction due to the curvature, and therefore cannot be elastically bent in the longitudinal direction so as to be convex in the other direction in the thickness direction. Conversely, the antenna member 320 can be elastically bent in the longitudinal direction so as to be convex in one direction in the thickness direction. In the example in Figure 3, at least the base portion of the antenna member 320 is curved in the width direction so as to be convex in a counterclockwise direction in a plan view. In this case, the antenna member 320 cannot be elastically bent in the longitudinal direction so as to be convex in the other direction in the thickness direction, i.e., clockwise in a plan view. That is, the antenna member 320 cannot be elastically bent in the longitudinal direction so as to be convex in a counterclockwise direction in a plan view, and therefore cannot be wound. Conversely, the antenna member 320 can be elastically bent in the longitudinal direction so as to be convex in one direction in the thickness direction, i.e., counterclockwise in a plan view. In other words, the antenna member 320 can be elastically bent and wound in a clockwise direction in a plan view along its longitudinal direction. The antenna member 320 may also be curved in a clockwise direction in a plan view along its width direction. In that case, the antenna member 320 can be elastically bent and wound in a counterclockwise direction in a plan view.

[0028] When the antenna member 320 is elastically bent in the longitudinal direction, the curvature of the antenna member 320 in the width direction is elastically reduced or eliminated. In other words, when the antenna member 320 is elastically bent in the longitudinal direction, the radius of curvature of the antenna member 320 in the width direction (the radius of curvature in a cross section perpendicular to the longitudinal direction) becomes elastically larger or nearly infinite.

[0029] Furthermore, in this embodiment, multiple antenna members 320 (four in this embodiment as an example) are wound around the support member 311 in a spiral shape in a clockwise direction when viewed from above. In this wound state, each antenna member 320 will have an adjacent antenna member 320 in a counterclockwise direction superimposed radially outward on it. Specifically, antenna member 320-2 superimposes antenna member 320-1 radially outward, and antenna member 320-3 superimposes antenna member 320-2 radially outward. Also, antenna member 320-4 superimposes antenna member 320-3 radially outward, and antenna member 320-1 superimposes antenna member 320-4 radially outward. At the positions where the antenna members 320 overlap, the thickness direction of the antenna member 320 is the radial direction. When the antenna members are stacked on top of each other, the inner surface 320b of the radially outer antenna member 320, which is located radially inward, and the outer surface 320a of the radially inner antenna member 320, which is located radially outward, are in contact with each other. With this configuration, compared to a configuration in which the antenna members 320-1 to 320-4 are wound separately, it is possible to wind them with a larger radius of curvature, making it easier to suppress plastic deformation of the antenna members 320-1 to 320-4.

[0030] In the process of housing the wound subassembly 300 inside the housing 200, a jig such as tape or cable tie is used to temporarily hold the winded state, and after housing the subassembly 300 inside the housing 200 in the wound state, the jig may be removed or cut. The housing 200 is an example of a housing member.

[0031] The antenna member 320 housed within the housing 200 extends radially outward within the housing 200, elastically pressing against the inner surface 200c of the housing 200. That is, in each antenna member 320, the outer surface 320a is in contact with the inner surface 200c at its outermost position.

[0032] Figure 4 is a side view (partially a cross-sectional view) showing the subassembly 300 protruding outside the housing 200. As shown in Figures 2 and 4, the antenna device 100 includes a coil spring 110 as an example of a biasing means for biasing the subassembly 300 toward the open side of the bottomed cylindrical housing 200, i.e., in the Z direction. The coil spring 110 is interposed between the bottom wall 311a of the support member 311 and the bottom wall 200a of the housing 200, and is a compression spring that is elastically compressed from the extended state in Figure 4 to the compressed state in Figure 2. The antenna device 100 also includes a locking device 210 that locks the subassembly 300 in place within the housing 200. The locking device 210 is configured to be electrically switchable between a locked state in which the subassembly 300 is kept inside the housing 200 and an unlocked state in which the locked state is released. When a release instruction signal is received from the locking device 210 in the locked state shown in Figure 2, the lock on the sub-assembly 300 is released, and it enters the unlocked state. As a result, the sub-assembly 300 moves relative to the housing 200 in the Z direction due to the elastic restoring force of the coil spring 110, and protrudes outside the housing 200 as shown in Figure 4. By protruding outside the housing 200, the constraint imposed by the housing 200 is removed, and the antenna member 320 enters an extended state due to its own elastic restoring force, resulting in the expanded state of the four antenna members 320 shown in Figure 1. The Z direction is an example of a first direction. The coil spring 110 and the locking device 210 are an example of an ejection mechanism.

[0033] As shown in Figures 2 and 3, the support member 311 has a support column 311b extending in the Z direction from the bottom wall 311a. As shown in Figure 3, the support column 311b is provided with a plurality of fixing parts 311b1 at predetermined intervals around the axis Ax in a plan view for fixing the antenna members 320. In this embodiment, the support column 311b has fixing parts 311b1 at 90° intervals around the axis Ax in a plan view for fixing four antenna members 320. At each fixing part 311b1, the antenna member 320 is fixed in a state where it is sandwiched between the fixing part 311b1 and the holding member 312. The fixing part 311b1 and the holding member 312 corresponding to each antenna member 320 have the same shape.

[0034] Figure 5 is a perspective view showing the vicinity of the part of the antenna device 100 where the antenna member 320 is fixed to the support member 311. The base portion of the antenna member 320 is fixed while sandwiched between the fixing portion 311b1 and the holding member 312. The fixing portion 311b1 and the holding member 312 are fixed together by a fastener 313 such as a bolt. The fixing portion 311b1 is provided with a convex curved surface 311c to bring the base portion of the antenna member 320 into the desired curved state, and the fixing portion 311b1 is provided with a concave curved surface 312a. The antenna member 320 is sandwiched between the fixing portion 311b1 and the holding member 312 with its inner surface 320b in contact with the convex curved surface 311c and its outer surface 320a in contact with the concave curved surface 312a. The convex surface 311c and the concave surface 312a extend substantially along the radial direction, and in the cross section intersecting the radial direction, the radius of curvature of the convex surface 311c is smaller than the radius of curvature of the concave surface 312a by the thickness of the antenna member 320. Furthermore, as shown in Figures 3 and 5, the outer circumferential surface 311d of the support member 311 is configured such that the tangential direction in plan view gradually changes to prevent abrupt bending of the antenna member 320 from the fixing portion 311b1 toward the outer periphery. The radius of curvature in plan view at each position of the outer circumferential surface 311d is set to be larger than a predetermined radius of curvature. This suppresses bending and plastic deformation of the antenna member 320.

[0035] [Antenna element] Figure 6 is a plan view of the antenna member 320A (320) of this embodiment, viewed in the thickness direction (circumferential direction of axis Ax) while it is extended and not curved in the width direction. This figure can also be said to represent the state of the antenna member 320 before it is bent in the width direction and longitudinal direction. In Figure 6, the X direction indicates the longitudinal direction of the antenna member 320, and the Y direction indicates the thickness direction of the antenna member 320. The Z direction indicates the width direction of the antenna member 320. The end of the antenna member 320 opposite to the X direction is supported by the support member 311. That is, the X direction is the direction away from the support member 311 and is the radial direction of axis Ax. The Y direction is the direction in which the antenna member 320 (the tip portion) is bent in the longitudinal direction and is the tangential direction of axis Ax in the circumferential direction. Furthermore, when the antenna member 320 is extended and attached to the support member 311, it extends radially along axis Ax with a curve that is convex in one direction in the width direction compared to the thickness direction.

[0036] As shown in Figure 6, the antenna member 320A of this embodiment includes a conductor member 321A (321) and an insulating member 322A (322). The conductor member 321 is formed in the form of a thin plate and strip with a substantially constant thickness. The conductor member 321 is made of a highly elastic metal material such as spring steel. On the other hand, the insulating member 322 is formed in the form of a thin film with a substantially constant thickness. The insulating member 322 is made of a synthetic resin material such as polyimide.

[0037] The conductor member 321 has a plurality of antenna elements (two as an example in this embodiment). One of the two antenna elements includes a conductor portion 321a, a conductor portion 321b2, and a conductor portion 321b3. This is referred to as the first antenna element. The conductor portion 321a extends in a strip shape in the X direction with a substantially constant width. The conductor portion 321b1 extends in a strip shape in the X direction from the conductor portion 321a with a substantially constant width that is narrower than the conductor portion 321a. The conductor portion 321b2 extends in the Z direction at the tip of the conductor portion 321b1. The conductor portion 321b3 extends in a strip shape in the opposite direction to the X direction from the conductor portion 321b2, at a position separated from the conductor portion 321b1 in the Z direction, with a substantially constant width that is narrower than the conductor portion 321a. The end 321d3 of the conductor portion 321b3 opposite to the X-direction is separated from the opposite end of the conductor portion 321a in the X-direction. That is, the end 321d3 is separated from the support member 311. The first antenna element is a bent antenna element that shortens the length in the X-direction while securing a longer element length, i.e., wavelength. Conductor portion 321b1 is an example of the first portion, conductor portion 321b2 is an example of a folded portion, and conductor portion 321b3 is an example of the second portion. Furthermore, this antenna element is an example of a folded antenna element.

[0038] One of the two antenna elements includes conductor portions 321a and 321c. This is referred to as the second antenna element. Conductor portion 321c extends in a band shape in the X direction from conductor portion 321b1 at a distance in the Z direction from conductor portion 321b1, with a width that is approximately constant and narrower than that of conductor portion 321a. The X-direction end 321d2 of conductor portion 321c is offset in the X direction from the X-direction end 321d3 of conductor portion 321b3. Also, as is clear from Figure 6, the distance from conductor portion 321b1 to conductor portion 321b3 is wider than the distance from conductor portion 321b1 to conductor portion 321c. Therefore, in the intermediate portion of the conductor member 321 in the X direction, conductor portions 321b1, 321c, and 321b3 are arranged in the Z direction with a distance between them. The conductive portion 321c is an example of a third portion. Furthermore, this antenna element is an example of a linear antenna element.

[0039] In this configuration, the element length of the first antenna element is longer than the element length of the second antenna element. Therefore, the wavelength of the first antenna element is longer than the wavelength of the second antenna element, and the operating frequency of the first antenna element is lower than the operating frequency of the second antenna element. The first antenna element can be used, for example, as an antenna in the 160 MHz band for VHF radio, and the second antenna element can be used, for example, as an antenna in the 400 MHz band for IoT wireless applications.

[0040] The insulating member 322A (322) extends in the X direction, i.e., the longitudinal direction, from a position that substantially overlaps with the end 321d3 of the conductor portion 321b3 in the thickness direction to a position that is further in the X direction than the X-direction end 321d1 of the conductor member 321. In the Z direction, i.e., the width direction, the insulating member 322A extends from a position that overlaps with the Z-direction opposite end 321e1 of the conductor member 321 to a position that overlaps with the Z-direction end 321e2. The insulating member 322A covers the conductor member 321 from at least one side in the thickness direction. The insulating member 322A can be integrated with the conductor member 321, for example, by adhesive. The insulating member 322 is an example of an insulator.

[0041] In this configuration, the insulating member 322A covers the conductor member 321 from at least one side in the thickness direction. With this configuration, the antenna member 320A becomes less prone to bending compared to the case where the insulating member 322A is absent.

[0042] Furthermore, in this configuration, the insulating member 322A is spanned between the conductor portion 321b1, the conductor portion 321c, and the conductor portion 321b3. This configuration makes it possible to suppress changes in the relative positions of the conductor portions 321b1, 321c, and 321b3. The insulating member 322 is an example of a retaining member.

[0043] Furthermore, in this configuration, the insulating member 322A covers the ends 321d1, 321d2, and 321d3 of the conductor member 321A in the X direction, and the ends 321e1 and 321e2 in the Z direction. As described above, as the subassembly 300 moves from a housed state to a protruding state, the antenna member 320 moves from a wound state to an extended state. At this time, the antenna member 320 slides against the inner surface 200c of the housing 200 and against the antenna member 320 that overlaps in the thickness direction in the Z direction (axial direction with respect to axis Ax) and the circumferential direction with respect to axis Ax. In this case, if the ends 321d1, 321d2, 321d3, 321e1, and 321e2 of the conductor member 321 are exposed, they may get caught on other members, which could hinder the axial and circumferential movement of the antenna member 320 with respect to axis Ax. Furthermore, in this case, there is a risk that the conductor member 321 may be damaged or deformed. In this embodiment, the ends 321d1, 321d2, 321d3, 321e1, and 321e2 of the conductor member 321 are covered by an insulating member 322. With this configuration, the conductor member 321 can move more smoothly in the axial and circumferential directions relative to the axis Ax, and damage and deformation of the conductor member 321 can be suppressed.

[0044] Furthermore, it is preferable that at least the conductive member 321 of the antenna member 320 is plastically deformed into a curved shape that is convex in one direction in the thickness direction in the width direction. This configuration provides the effect of more reliably obtaining and increasing the elastic restoring force of the antenna member 320.

[0045] As described above, in the antenna device 100 of this embodiment, the insulating member 322A (holding member, insulator) can suppress deformation of the antenna member 320A and changes in the relative positions of the conductor parts 321b1, 321b3, and 321c. With this configuration, changes in the electrical characteristics of the antenna due to such deformation or changes in relative positions can be suppressed.

[0046] Furthermore, in this embodiment, the insulating member 322A can suppress changes in the relative positions of the conductive portions 321b1 and 321c included in another antenna element. With this configuration, it is possible to suppress changes in the electrical characteristics of each antenna due to changes in the relative positions of the conductive portions 321b1 and 321c.

[0047] Furthermore, in this embodiment, the insulating member 322A can suppress changes in the relative positions of other conductive portions 321b1 (first portion) and 321b3 (second portion) included in the folded antenna element, which is the same antenna element. With this configuration, it is possible to suppress changes in the electrical characteristics of the antenna due to changes in the relative positions of the antenna element.

[0048] Furthermore, in this embodiment, as described above, the insulating member 322A can suppress changes in the relative positions of the conductor portions 321b1, 321b3, and 321c. That is, the relative positions of the three conductor portions—the two conductor portions 321b1 and 321b3 included in the folded antenna element, and the conductor portion 321c included in the linear antenna element—can be suppressed by a single insulating member 322A. With this configuration, compared to a configuration in which changes in the relative positions of the three conductor portions 321b1, 321b3, and 321c are suppressed by more holding members, the number of parts is reduced, thereby further reducing manufacturing effort and costs.

[0049] Furthermore, in this embodiment, the operating frequency of the folded antenna element is lower than that of the linear antenna element. With this configuration, the antenna device 100 can function as two antennas with different operating frequencies. In addition, the folded antenna element with a long element length and the linear antenna element with a short element length can be concentrated in a narrower area of ​​the antenna member 320, and consequently, the antenna device 100 can be made more compact.

[0050] Furthermore, in this embodiment, the cross-section of at least the base portion of the antenna member 320 that intersects the X direction (extension direction, longitudinal direction) is curved convexly in the thickness direction of the antenna member 320. With this configuration, the rigidity of the antenna member 320 can be increased, making it less likely for the antenna member 320 to deform in the extended state. In addition, the elastic restoring force from the coiled state to the extended state of the antenna member 320 can be increased, resulting in the effect that the antenna member 320 can be extended more quickly or more reliably. In other words, the desired extended state (unfolded state) can be obtained more easily.

[0051] Furthermore, in this embodiment, the support member 311 is supported in a state in which the base portion is curved convexly in the thickness direction in the width direction. With this configuration, the bending rigidity of the antenna member 320 can be increased more reliably, and the elastic restoring force from the wound state to the extended state can be increased more reliably.

[0052] Furthermore, in this embodiment, the conductor member 321 constituting the antenna element is plastically formed into a shape that is convex in the thickness direction in the width direction. This configuration makes it possible to further increase the bending rigidity of the antenna member 320 and to further increase the elastic restoring force from the wound state to the extended state.

[0053] Furthermore, in this embodiment, when wound, the multiple antenna members 320-1 to 320-4 (first antenna members) are wound around the support member 311 so that they overlap each other in their thickness direction. With this configuration, compared to a configuration in which the antenna members 320-1 to 320-4 are wound separately, it is possible to wind them with a larger radius of curvature, making it easier to suppress plastic deformation of the antenna members 320-1 to 320-4.

[0054] Furthermore, in this embodiment, the insulating member 322 is formed in the form of a thin film and covers the conductor member 321 in a state that overlaps at least partially in the thickness direction. With this configuration, the thin film insulating member 322 can be fixed to the conductor member 321 relatively easily.

[0055] Furthermore, in this embodiment, the insulating member 322 covers the ends 321d1, 321d2, 321d3, 321e1, and 321e2 of the conductor member 321. With this configuration, when the antenna member 320 moves from an extended state to a wound state, it is possible to prevent the antenna member 320 from getting caught on other members at the ends 321d1, 321d2, 321d3, 321e1, and 321e2. Consequently, it is possible to prevent the antenna member 320 from becoming difficult to unfold, or from being damaged or deformed.

[0056] Furthermore, in this embodiment, the antenna device 100 is equipped with a coil spring 110 and a locking device 210 as an ejection mechanism that moves the subassembly 300 housed in the housing 200 (housing member) relative to the housing 200 in the Z direction and ejects it to the outside of the housing 200. With the subassembly 300 outside the housing 200, the antenna member 320 moves from a wound state to an extended state due to its elasticity. With this configuration, the extended and deployed state of each antenna member 320 can be realized with a relatively simple structure.

[0057] The following describes some variations of the antenna member 320. Each variation provides the same effects as the embodiment described above, based on the same configuration.

[0058] [First variation] Figure 7 is a plan view of the antenna member 320B(320) of the first modified example. As shown in Figure 7, in this modified example, the insulating member 322B(322) extends beyond the ends 321d1, 321d3 in the X direction and beyond the ends 321e1, 321e2 in the Z direction. With this configuration, it is possible to further suppress the antenna member 320 from getting caught on other members at its ends when it protrudes in the Z direction and when it changes from a wound state to an extended state. Consequently, it is possible to further suppress the antenna member 320 from becoming difficult to unfold, or from being damaged or deformed.

[0059] [Second variation] Figure 8 is a plan view of the antenna member 320C(320) of the second modified example. As shown in Figure 8, in this modified example, an insulating member 322C1 covering end 321d1, an insulating member 322C2 covering ends 321d2 and 321d3, and an insulating member 322C3 covering the X-direction end 321d4 of the conductor portion 321a are each provided separately. With this configuration, the insulating member 322 can be made smaller, and thus the mass of the insulating member 322, and consequently the mass of the antenna member 320C, can be reduced.

[0060] Furthermore, on the side closer to the conductor portion 321b2 than the intermediate position, the relative position is less likely to change because the conductor portion 321b1 and the conductor portion 321b3 are connected by the conductor portion 321b2. In this modified example, the insulating member 322C2 is spanned between the conductor portion 321b1 and the portion of the conductor portion 321b3 that is further away from the conductor portion 321b2 (folded portion) than the intermediate position of the conductor portion 321b3 in the X direction. Therefore, the relatively small insulating member 322C2 can effectively suppress changes in the relative position between the conductor portion 321b1 and the conductor portion 321b3.

[0061] [Third variation] Figure 9 is a plan view of the antenna member 320D(320) of the third modified example. As shown in Figure 9, in this modified example, the conductor member 321D(321) has a shape that is symmetrical with respect to a virtual plane intersecting the Z direction with respect to the conductor member 321A of the above embodiment and modified example. This configuration also provides the same effects as the above embodiment and modified example. Furthermore, in this modified example, since the step can be eliminated at the end 321e1 in the Z direction, which is the direction in which the subassembly 300 protrudes, the antenna member 320D is less likely to get caught on other members when it moves in the Z direction. Consequently, the antenna member 320 is less likely to become difficult to unfold, and the antenna member 320 is less likely to be damaged or deformed. In addition, in this modified example, the insulating member 322D covers all ends of the conductor member 321D in the X and Z directions. With this configuration, the antenna member 320 can be further prevented from catching on other members at its end when it protrudes in the Z direction and changes from a wound state to an extended state. Consequently, the antenna member 320 can be further prevented from becoming difficult to unfold, or from being damaged or deformed.

[0062] [Fourth variation] Figure 10 is a plan view of the antenna member 320E(320) of the fourth modified example. As shown in Figure 10, in this modified example, the conductor member 321E has a shorter conductor portion 321b3 compared to the conductor members 321A and 321D of the above embodiment and modified examples, and does not overlap with the conductor portion 321c in the Z direction. Even with a conductor member 321E of this shape, the insulating members 322E(322E1~322E4)) can suppress changes in the relative positions of the conductor portion 321b1 and the conductor portion 321b3, and the relative positions of the conductor portion 321b1 and the conductor portion 321c. In this modified example, four insulating members 322E1~322E4 are provided, but the invention is not limited to this, and insulating members 322 similar to those in the above embodiment and other modified examples may be provided.

[0063] Although embodiments of the present invention have been illustrated above, these embodiments are merely examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, each configuration, shape, and other specifications (structure, type, orientation, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate. [Explanation of Symbols]

[0064] 1…Artificial satellite 100... Antenna device 110... Coil spring (discharge mechanism) 200... Enclosure (Housing component) 200a…Bottom wall 200b…peripheral wall 200c...inner 210... Locking device (discharge mechanism) 300... Subassembly 311...Support member 311a…Bottom wall 311b…Strut part 311b1…Fixed part 311c…Convex curved surface 311d…Outer surface 312... Retaining member 312a…Concave curved surface 313…Fixing tool 320, 320A~320E… Antenna components 320-1~320-4…Antenna components (First antenna component) 320a…External surface 320b...Inside 321, 321A, 321D, 321E… Conductor components 321a...Conductor part (antenna element) 321b1…Conductor part (antenna element, first part) 321b2…Conductor portion (antenna element, folded portion) 321b3…Conductor part (antenna element, second part) 321c... Conductor part (antenna element, third part) 321d1, 321d2, 321d3, 321d4, 321e1, 321e2...end 322, 322A, 322B, 322C, 322C1~322C3, 322D, 322E, 322E1~322E4... Insulating members (holding members, insulators) Ax…Axis X…direction Y... Direction Z…direction

Claims

1. An antenna device for an artificial satellite having an antenna member that has a roughly strip-like shape and is used in an elastically extended, strip-like state after the winding state in the longitudinal direction is released, In the extended state, the antenna member is At least one antenna element formed in the shape of a thin plate, Multiple conductive portions included in the same antenna element, extending in a strip-like manner in the extension direction of the antenna member in the extended state and spaced apart in the width direction of the antenna member, A thin-film holding member is provided for each antenna element, spans between the multiple conductor portions at positions where the multiple conductor portions face each other, and suppresses changes in the relative positions of the multiple conductor portions while maintaining the insulating state between the multiple conductor portions; An antenna device for artificial satellites that has the following features.

2. The antenna device for an artificial satellite according to Claim 1, wherein the holding member partially covers the antenna element.

3. The antenna device for an artificial satellite according to claim 1 or 2, wherein the operating frequencies of the plurality of conductive parts are different.

4. The antenna member is provided with a support member that cantilever-supports it in the extended state, The antenna element is a folded antenna element having, in the extended state, a first portion that extends in a strip shape away from the support member, a folded portion that extends in the width direction of the antenna member at the tip of the first portion, and a second portion that extends in a strip shape from the folded portion toward the support member to a position away from the support member, at a position spaced apart from the first portion in the width direction of the antenna member. The antenna device for an artificial satellite according to claim 1 or 2, wherein the plurality of conductive portions are a part of the first portion and the second portion.

5. The antenna device for an artificial satellite according to claim 4, wherein the holding member is spanned between at least a portion of the second portion that is further away from the folded portion than the longitudinal middle portion of the second portion and the first portion.

6. The plurality of conductive portions include a third portion which is part of a linear antenna element that extends in a strip shape from the support member, separate from the folded antenna element. The antenna device for an artificial satellite according to claim 4, wherein the holding member is spanned between the first part, the second part, and the third part.

7. The antenna device for an artificial satellite according to claim 6, wherein the operating frequency of the folded antenna element is lower than the operating frequency of the linear antenna element.

8. The antenna device for an artificial satellite according to claim 4, wherein the cross-section of the antenna member intersecting the longitudinal direction is curved convexly in the thickness direction of the antenna member, at least at the base portion of the antenna member supported by the support member.

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