Extension mast

Abstract

To provide an extension mast that is adopted to a use in an environment with a restriction such as lunar, can be housed compactly and developed, and is configured as an antenna integrated type.SOLUTION: An extension mast 200 at least comprises: a top board 2; a bottom board 1; a plurality of elastic vertical beams 3 connecting the top board 2 and the bottom board 1; add a wiring 70 which is connected to the top board 2 via a hole part 4 provided to the bottom board 1 to energize to each elastic vertical beam 3 between the top board 2 and bottom board 1 to contract it in a coli shape, and which releases the energization and stretches each elastic vertical beam 3 linearly. A first part 9d of the wiring 70 on the bottom board side is constituted by a cable 9 in order to be connected to an antenna element as an antenna integrated type.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an extension mast, and more particularly to an extension mast configured with an integrated antenna. [Background technology]

[0002] Examples of commonly known existing technologies for masts with antennas include Non-Patent Document 1 and Patent Document 1.

[0003] The hydraulic telescopic mast disclosed in Non-Patent Document 1 etc. can be installed, for example, on a mobile station base station vehicle, and the pole (mast) can be extended and retracted by changing the amount of oil sent from the hydraulic tank, and an antenna can be attached to the telescopic tip of the pole. The wire-type telescopic mast disclosed in Patent Document 1 etc. is extended and retracted by pushing and pulling a wire threaded through the pole with an electric motor, and is generally used as an automobile antenna, etc.

[0004] Furthermore, as an existing technology that can also be used for antenna deployment in spacecraft systems, there is the extendable boom disclosed in Non-Patent Document 2 and the like. Known methods include a self-extending method in which an elastic boom with a membrane structure is wound and stored, and the boom is extended simply by releasing the elastic energy, and a method in which the power of a drive motor is also used to extend the boom. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 05-009009 [Patent Document 2] Special Publication No. 6-13776 [Patent Document 3] Special Publication No. 6-31080 [Patent Document 4] Publication number 7-39760 [Patent Document 5] Publication No. 7-2400 [Patent Document 6] Publication number 6-26480 [Non-patent literature]

[0006] [Non-Patent Document 1] Telescopic pole system for radio wave measurement, 2021, (Yuasa Machinery Co., Ltd.), [Searched on September 15, 2023], Internet<URL:http: / / www.yuasakk.co.jp / pole / mast04.html> [Non-Patent Document 2] Furuya, H.; Sakamoto, H. Space Deployable Structure Composed of Extendible Boom and Membrane. Journal of the Japan Society for Aeronautical and Space Sciences, 2016, 64.11: 322-326. Summary of the Invention [Problem to be solved by the invention]

[0007] However, conventional technology has been unable to address the demand for compact storage and deployment of an antenna mast for use on the lunar surface.

[0008] Here, there is a demand for a mast with an antenna for use on the moon for the following reasons. That is, in order to build a mobile phone area such as 5G on the moon's surface for the development of lunar resources, it is necessary to attach an antenna to a mast of several tens of meters and install it on the moon's surface. In order to reduce the amount of construction on the moon, where the working environment is worse than on Earth, it is desirable to attach the antenna and cables to the mast on Earth beforehand and then transport it to the moon. The space available on a spacecraft for mounting equipment is limited, so the mast with an antenna needs to be stored compactly. Furthermore, it is also necessary to be able to deploy the mast with an antenna with simple operations after arriving on the moon's surface.

[0009] In contrast, everyday masts with antennas such as those described in Non-Patent Document 1 and Patent Document 1 require drive devices such as hydraulic devices and motor devices, and if these were used as is in a mast with antennas for use on the lunar surface, extra space would be required to accommodate the drive devices, sacrificing compactness, making them unsuitable for use on the lunar surface after being transported by a spacecraft. The extension boom in Non-Patent Document 2 may be suitable for deployment in a flat plane, but is not necessarily suitable for efficient deployment in a straight line as a mast of several tens of meters in length.

[0010] Furthermore, in the case of a mast equipped with an antenna for use on the lunar surface, the space required for mounting the antenna must be kept as compact as possible, but conventional technology has been unable to address this issue.

[0011] Furthermore, while there are prior art technologies such as Patent Documents 2 to 6 that describe extension masts that can be deployed in a straight line, these extension masts are general-purpose products, and there is no disclosure of how the space required for attaching an antenna to an extension mast should be kept as compact as possible.

[0012] In view of the problems with the conventional technology described above, an object of the present invention is to provide an extendable mast with an integrated antenna that can be compactly stored and deployed and is suitable for use in restrictive environments such as the surface of the moon. [Means for solving the problem]

[0013] In order to achieve the above-mentioned object, the present invention provides an extension mast comprising at least a top plate, a bottom plate, a plurality of elastic vertical beams connecting the top plate and the bottom plate, and a pull rope connected to the top plate through a hole provided in the bottom plate, thereby applying force to the elastic vertical beams between the top plate and the bottom plate to contract them into a coil shape, and releasing the force to extend the elastic vertical beams in a straight line, wherein the first part of the pull rope on the bottom plate side is composed of a cable for connecting to an antenna element, and thus configured as an integrated antenna. Effect of the Invention

[0014] According to the invention, the cables connecting the antenna elements act as tow ropes for the extension mast, making it possible to configure the extension mast as an integrated antenna that can be stored and deployed compactly and is suitable for use in restrictive environments. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing the main structure and deployment mode of an existing extension mast. [Diagram 2] FIG. [Diagram 3] FIG. 13 is an explanatory diagram of how to install the diagonal rope. [Figure 4] FIG. 2 is a configuration diagram of an extension mast according to one embodiment. [Diagram 5] FIG. 2 is a diagram showing the structure of an antenna element. [Figure 6] FIG. 1 is a diagram showing an example of a two-frequency, two-branch configuration as an example of an extendable mast having a plurality of antenna elements. [Figure 7] FIG. 1 is a diagram showing an example of a one-frequency, four-branch configuration as an example of an extendable mast having a plurality of antenna elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In an embodiment of the present invention, an extendable mast (coilable extendable mast) disclosed in Patent Documents 2 to 6, etc. and available from the applicant (Nippon Aircraft Co., Ltd.) can be used as a base structure for compactly storing and deploying the antenna.

[0017] For the purpose of explanation, the base extension mast is assumed to be an existing extension mast 100. In an embodiment of the present invention, the existing extension mast 100 can be used as a structure for deployment, and an antenna-integrated extension mast 200 (abbreviated as extension mast 200) can be used, which is an additional design that integrates an antenna into the existing extension mast 100. In the following, the existing extension mast 100 will be explained as an existing technology, as a premise for explaining the extension mast 200 according to an embodiment of the present invention.

[0018] The basic configuration of the existing extendable mast 100 is disclosed in Patent Document 2, and while the basic configuration has three vertical beams, Patent Document 3 discloses an example in which the basic configuration has five or more vertical beams. Patent Document 5 discloses an example in which a spring member or spring is added to the basic configuration for forced raising at the initial stage of deployment. Patent Document 5 discloses an example in which a spring member is added to the basic configuration to reduce deformation of the cross beams. Patent Document 6 discloses an example in which the cross beams are improved for the basic configuration.

[0019] As the existing extension mast 100, only the basic configuration of Patent Document 2 (including modified examples and conventional examples) may be used, or the basic configuration may be modified in whole or in part as described in Patent Documents 3 to 6.

[0020] Fig. 1 shows the main structure and unfolding mode of the existing extension mast 100, and the unfolding states are shown as states C1, C2, and C3. Regarding the existing extension mast 100, state C1 shows the contracted state (fully folded state), state C2 shows the state in the middle of extension, and state C3 shows the extended state (fully extended state). The existing extension mast 100 has a structure in which a circular bottom plate 1 and a top plate 2 are connected by multiple (e.g., three) elastic vertical beams 3 that act as extension columns and are made of an elastic material such as fiber-reinforced resin.

[0021] The bottom plate 1 has a hole 4 at its center for allowing the pull rope 7 to pass through and move up and down, and the pull rope 7 is fixed to the center of the top plate 2 from the inside through the hole 4. By pulling the pull rope 7 in the contraction direction D2 from the top plate 2 toward the bottom plate 1 by hand or by some kind of pull rope winding mechanism, a force is applied to the top plate 2 toward the bottom plate 1, and the elastic vertical beams 3 of the existing extension mast 100 are folded and deformed from a linear extension state into a coil shape, so that the existing extension mast 100 can contract from state C3 → C2 → C1. Conversely, when the pull rope 7 is released in the contraction state C1 (the part that was pulled and stopped is released), the existing extension mast 100 can autonomously extend in the extension direction D1 from state C1 → C2 → C3 only by the elastic energy stored in the elastic vertical beams 3, etc. (without requiring any other driving force such as a motor).

[0022] That is, when a pulling force is applied by the pulling rope 7, the elastic vertical beam 3 is biased, and the existing extension mast 100 contracts from state C3 to C2 to C1. When the pulling force by the pulling rope 7 is released, the biasing force on the elastic vertical beam 3 is also released, and the existing extension mast 100 extends from state C1 to C2 to C3. (Note that, with regard to the extension mast 200 according to the embodiment of the present application, when contracting, the pulled pulling rope 7 may be fixed with a fastener (not shown), and when extending on the lunar surface, the fastener may be removed by using part of the power for opening the door that houses the extension mast 200. Alternatively, extension on the lunar surface may be performed by some kind of pulling rope 7 winding mechanism using a motor (which may not be a dedicated item for winding the pulling rope 7 but may also be used for other purposes).)

[0023] Note that, instead of fixing the pulling cord 7 to the center of the tabletop 2 as in Patent Document 2, a hole (not shown) may also be provided in the center of the tabletop 2, the pulling cord 7 may be passed through the hole, and then the pulling cord 7 may be connected to a diagonal cord (described later) formed at the top, thereby enabling the tabletop 2 to be contracted and extended more smoothly. In this configuration, the pulling cord 7 is in contact with the tabletop 2, and the tabletop 2 and the pulling cord 7 are not fixed but are mechanically connected, so the action of pulling the tabletop 2 remains the same.

[0024] In addition, since the existing extension mast 100 can be deformed in various ways as described in, for example, Patent Documents 2 to 6, when the existing extension mast 100 is contracted / extended, something other than the elastic vertical beam 3 may be used as the elastic member for biasing / releasing the bias by the pulling rope 7, but at least the elastic vertical beam 3 is the object for biasing / releasing the bias by the pulling rope 7.

[0025] The existing extension mast 100 has a cross beam 5 (described later) as a structure that is directly or indirectly (depending on the deformation of the elastic vertical beam 3 by the pull rope 7) biased / unbiased by the pull rope 7, and may also have a spring member or spring mechanism (not shown) disclosed in Patent Document 5 to improve the initial extensibility when extending from state C1 to C2 to C3, or a spring member (not shown) disclosed in Patent Document 5 that has the effect of reducing deformation of the cross beam 5 may be provided on the "diagonal rope" described later.

[0026] A plurality of elastic cross beams 5 are provided on the three elastic vertical beams 3 at regular intervals in the extension direction in an extended state, and are fixed to the elastic vertical beams 3. Fig. 2 is a front view of the cross beam 5, in which the cross beam 5 is fixed to the elastic vertical beams 3 at the tips of three straight portions 5b that are arranged radially from the center at angles of 120° to each other, and a hole portion 5a is formed at the center where the three straight portions 5b are connected, through which the pulling rope 7 passes and through the cross beam 5 (passing through the pulling rope 7). By providing the cross beams 5, it is possible to stably perform contraction / extension of the existing extension mast 100.

[0027] The existing extension mast 100 may further be provided with an oblique rope (diagonal cord) (not shown in FIG. 1 etc. for the sake of simplicity of the drawings) stretched in an X-shape so as to connect two pairs of vertical beams 3, 3 for each vertically adjacent horizontal beam 5, 5 as a configuration for stabilizing the contraction / extension of the mast. The oblique rope is also disclosed in Patent Document 2 etc. FIG. 3 is an explanatory diagram of how to provide the oblique rope, and the vertically adjacent horizontal beams 5, 5 are shown as an upper horizontal beam 5u and a lower horizontal beam 5d with a distinction between the upper and lower beams. The tip end ua, ub, uc of the upper horizontal beam 5u and the tip end da, db, dc of the lower horizontal beam 5d indicate the locations where the beams are fixed to the vertical beams 3 (not shown, but distinguished as 3a, 3b, 3c). In this case, for example, for the adjacent vertical beams 3b, 3c, the oblique rope may be provided between the points ub, dc and between the points uc, db so as to cross in an X-shape between the upper horizontal beam 5u and the lower horizontal beam 5d. The diagonal ropes may be fixed to the longitudinal beams 3 or the transverse beams 5 at the locations ub, dc and uc, db where they are provided.

[0028] The above describes an extension mast 200 (with integrated antenna) according to an embodiment of the present invention, based on the existing extension mast 100. Fig. 4 is a configuration diagram of the extension mast 200 according to one embodiment, showing the configuration in a state corresponding to state C3 of the existing extension mast 100, i.e., in the extended state. The extension mast 200 is the same as the existing extension mast 100, except that the pulling rope 7 in the existing extension mast 100 is replaced with an antenna-directed pulling rope 70. Therefore, the same structures in the extension mast 200 as those in the existing extension mast 100 (such as the bottom plate 1, top plate 2, elastic vertical beams 3 and horizontal beams 5, as well as the diagonal ropes not shown) are given the same reference numerals.

[0029] The antenna-directed lead rope 70 includes an upper lead rope 7u fixed from the inside to the center of the top plate 2, an antenna element 80 provided on one of the elastic vertical beams 3, and a coaxial cable 9 for power supply connected to the antenna element 80 (shown by a thick black line in the figure). (However, a portion of the coaxial cable 9 is configured not to receive tensile stress as a lead rope, as described later.) The upper lead rope 7u is configured as an independent lead rope (string) separate from the coaxial cable 9. The coaxial cable 9 is fixed to the upper lead rope 7u at an upper point n close to the top plate 2 by, for example, tying the upper lead rope 7u to the upper lead rope 7u. The portion of the coaxial cable 9 above the point n is called the upper cable portion 9u, and the portion below the point u is called the lower cable portion 9d to distinguish between the two portions.

[0030] The upper cable portion 9u is provided with an antenna element 8 at its tip, which is opposite to the point n, and this antenna element 8 is formed on one elastic longitudinal beam 3.

[0031] In this embodiment, the role of the pulling rope 7 of the existing extension mast 100 is played by the upper rope part 7u and the lower cable part 9d fixed to the upper rope part 7u at a point n. In other words, in this embodiment of the present invention, the conventional pulling rope 7 (the part farther from the top board 2) is realized not by a dedicated pull cord, but by using the lower cable part 9d of a coaxial cable 9 that can also be used as a pull cord, thereby making the coaxial cable 9 play the role of the pulling rope 7.

[0032] Here, the upper cable portion 9u to which the antenna element 8 is connected is designed to have a sufficient length so that the upper cable portion 9u is bent even when the upper cable portion 7u and the lower cable portion 9d, which play the role of the "pull string (conventional pull rope 7)", are pulled, so that no pulling force is applied to the connection point of the antenna element 8. Alternatively, the upper cable portion 9u may be installed on one of the three straight portions 5b of the cross beam 5 described in FIG. 2 with or without being bent (for example, the upper cable portion 9u may be attached to the surface of the straight portion 5b and installed as an integrated unit). The cross beam 5 is made of an elastic material but a material harder than the coaxial cable 9, so that the tensile stress is prevented from being applied to the upper cable portion 9u or is prevented from being applied significantly (i.e., the effect of the stress is eliminated, or if it cannot be eliminated, it is mitigated to a certain extent).

[0033] In the example of FIG. 4, the cross beams 5 (cross beams 5 that can be provided at approximately equal intervals in the vertical direction along the elastic vertical beams 3) are not present above the position n, and the antenna element 8 is depicted as if it were installed near the highest position near the top plate 2 in the height direction of the extension mast 200 in the extended state. However, the height at which the antenna element 8 is arranged on the extension mast 200 in the extended state may be any height on the elastic vertical beams 3. That is, one or more cross beams 5 may be arranged along the upper side rope portion 7u. For example, assuming that 20 cross beams 5 appear in the height direction in the extension mast 200 in the extended state, the antenna element 8 may be arranged at the 10th height position in the middle, and the "position n" may be formed at that position, and the upper side rope portion 7u may be formed in the range above this position n where 10 cross beams 5 appear.

[0034] The same applies to the examples of Figs. 6 and 7 described later, and the number of cross beams 5 shown is merely illustrative, and the height at which the antenna elements 8 are arranged may be arbitrary.

[0035] FIG. 5 is a diagram showing an example of the structure of the antenna element 8. The antenna element 8 can be manufactured as a thin metal film covering the surface of the elastic vertical beam 3 made of resin or the like by plating the surface of the elastic vertical beam 3. For example, as a λ / 4 wavelength dipole antenna, the outer periphery of the elastic vertical beam 3 is covered with a plated portion at equal lengths in the vertical direction to form the antenna element 8 as an upper plated portion 8u and a lower plated portion 8d, and wirings wu and wd are provided to connect to the coaxial cable 9. The example of FIG. 5 shows an example in which the cross-sectional shape of the elastic vertical beam 3 is a circle, but even if the cross-section is formed in another shape, such as a square or a triangle, the antenna element 8 can be formed by covering two places with plated portions at equal lengths in the vertical direction. The number of antenna elements 8 varies depending on the type of antenna (dipole, monopole, etc.). A balun, a matching circuit, a conversion circuit, etc. may be connected between the antenna element 8 and the coaxial cable 9. The antenna formed of the antenna element 8 may be formed for any of the following purposes: transmission, reception, and shared transmission and reception.

[0036] As an example developed from the embodiment of FIG. 4, an extendable mast 200 may be used to provide a plurality of antenna elements 8, as shown in FIGS.

[0037] In the example of FIG. 6, antenna elements of different frequencies are plated at different positions to configure a multi-frequency configuration, and two different power supply cables 91, 92 are used to support multi-branching (multi-antenna). The first power supply cable 91 is divided into a first antenna element 81u of a first frequency and a second antenna element 81d of a second frequency through a first splitter d1 to realize multi-frequency. Similarly, the second power supply cable 91 is divided into a first antenna element 82u of a first frequency and a second antenna element 82d of a second frequency through a second splitter d2 to realize multi-frequency. The upper side cable portion 7u, these cables 91, 92, and antenna elements 81u, 81d, 82u, 82d constitute the antenna-directed lead 70, and as in the example of FIG. 4, a portion of the cables 91, 92 is configured not to receive tensile stress as a lead ray, as described later.

[0038] Here, since the first and second duplexers d1 and d2 are used, as shown in FIG. 6, antenna elements of different frequencies may be arranged at different positions (in the vertical direction of the elastic vertical beam 3). For example, the first antenna element 81u of the first frequency is arranged at a higher position than the second antenna element 81d of the second frequency via the first duplexer d1. Similarly, the first antenna element 82u of the first frequency is arranged at a higher position than the second antenna element 82d of the second frequency via the second duplexer d2. In addition, the height positions of antenna elements of the same frequency may or may not be aligned. This is an example in which the heights of the two first antenna elements 81u and 82u of the first frequency are not aligned, and the heights of the two antenna elements 81m and 82m of the second frequency are aligned.

[0039] In the example of Fig. 6, the wiring near the four antenna elements 81u, 81m, 82u, and 82m is configured as cable parts 91u, 91m, 92u, and 92m, and similarly to the case of the upper cable part 9u in Fig. 4, the cable parts 91u, 91m, 92u, and 92m may be bent and connected to the elastic vertical beam 3 or placed on the horizontal beam 5 so as not to be subjected to tensile stress when the pulling cord is pulled. In addition, the antenna element 81u at the highest position among the four antenna elements 81u, 81m, 82u, and 82m may be configured as a part for forming the part n similar to Fig. 4, and the part above the part n may be configured as the upper side rope part 7u (as a rope part separate from the cable of the present application). In the part below the part n, the first power supply cable 91 and the second power supply cable may be bundled together by tying them together, etc., and configured as a part corresponding to the lower cable part 9d in Fig. 4 so as to function as a single pulling cord (pulling string).

[0040] 6, similarly to the example of Fig. 4, the upper rope portion 7u and, at a location below the point n, the first power feed cable 91 and the second power feed cable 92 (if both cables are present at that height) bound together by tying them together or the like can be used as a configuration that fulfills the role of the conventional pulling rope 7. (For example, at a height just below the point n, only the first power feed cable 91 is present, so there is no need to tie it together with the second power feed cable 92 or the like.)

[0041] Each of the four antenna elements 81u, 81m, 82u, and 82m can be formed by plating the elastic vertical beam 3, similarly to the antenna element 8 described with reference to FIG.

[0042] As described above, the example of FIG. 6 is an example of a two-frequency two-branch configuration. Similarly, FIG. 7 shows an example of a one-frequency four-branch configuration. Here, four different power supply cables 93, 94, 95, 96 are provided as four branches, and antenna elements 83, 84, 85, 86 of the same frequency are provided in each. Here, the antenna elements 83, 84 are at the same height, and the antenna elements 85, 86 are at a different height and are arranged at the same height, but the height of the location where each antenna element 83, 84, 85, 86 is arranged may be arbitrary. The antenna-directed lead rope 70 is composed of the upper side lead rope portion 7u, these cables 93, 94, 95, 96, and the antenna elements 83, 84, 85, 86, and as in the example of FIG. 4, a portion of the cables 93, 94, 95, 96 is configured not to receive tensile stress as a lead rope, as described later.

[0043] Also, the nearby wiring of each antenna element 83, 84, 85, 86 is configured as cable portions 93u, 94u, 95u, 96u, and similarly to the upper cable portion 9u in Fig. 4, it is sufficient to bend and connect to the elastic vertical beam 3 or place on the horizontal beam 5 so as not to be subjected to tensile stress when the pulling cord is pulled. Also, similarly to the examples in Figs. 4 and 6, the highest position of the cable portions 93u, 94u, 95u, 96u of the nearby wiring is formed as a point n, and the portion above point n is configured as the upper side rope portion 7u, and at point n, the corresponding cable is fixed to the upper side rope portion 7u. (In the example in Fig. 7, the power supply cables 93, 94 are fixed to the upper side rope portion 7u at the same point n.)

[0044] Below point n, all of the power supply cables 93, 94, 95, and 96 present at each height are bundled together by tying them together or the like so that they function as a single pull rope, and the bundled point where the cables are tied together or the like (which corresponds to the lower cable portion 9d in Figure 4) and the upper rope portion 7u can function as the conventional pull rope 7.

[0045] As described above, in the extension mast 200 of this embodiment, the configuration of the antenna elements is not limited to the one-frequency, one-branch configuration as shown in Fig. 4, but it is also possible to use a two-frequency, two-branch configuration as shown in Fig. 6 or a one-frequency, four-branch configuration as shown in Fig. 7. In a similar manner, for any natural numbers n, m ≧ 1, the extension mast 200 of this embodiment can be realized with an n-frequency, m-branch configuration.

[0046] As described above, according to the embodiment of the present invention, the role of the conventional towing rope 7 is performed by configuring the side farther from the top plate 2 with a power supply cable that connects to the antenna element, and by having this power supply cable take on the role of the towing rope 7, it is possible to configure the extendable mast 200 with an antenna integrated into the structure of the existing extendable mast 100. This allows the extendable mast 200 as a mast with an antenna to be stored and deployed compactly, thereby saving space when installed on a spacecraft.

[0047] For example, it is conceivable to place an antenna element on the top plate 2 of an existing extendable mast 100, but the extendable mast 200 of this embodiment does not adopt such a configuration, and as explained in Fig. 5 etc., the antenna element is configured compactly by plating the outer peripheral surface of the elastic vertical beams 3 with almost no change to the shape of the elastic vertical beams 3 themselves. Therefore, the space above the top plate 2 can be used as a space for installing a separate sensor device other than the antenna, and the space on the spacecraft can be effectively utilized while saving it.

[0048] By contributing to lunar resource development, etc., an embodiment of the present invention can contribute to Goal 9 of the United Nations-led Sustainable Development Goals (SDGs) "Develop resilient infrastructure, promote sustainable industrialization and foster innovation." [Explanation of symbols]

[0049] 100...Existing extension mast, 200...(antenna integrated) extension mast, 1...Bottom plate, 2...Top plate, 3...Elastic vertical beam, 4...Hole, 5...Horizontal beam, 7...Rope, 70...Rope for antenna, 7u...Upper rope, 80...Antenna element, 9...Coaxial cable (power supply cable), n...Location, 9u...Upper cable portion, 9d...Lower cable portion, 8u...Upper plated portion, 8d...Lower plated portion, wu, wd...Wiring

Claims

1. An extension mast including at least a top plate, a bottom plate, a plurality of elastic vertical beams connecting the top plate and the bottom plate, and a pull rope connected to the top plate through a hole provided in the bottom plate, which pulls the elastic vertical beams between the top plate and the bottom plate to contract them in a coil shape and releases the pull rope to extend the elastic vertical beams in a linear shape, 2. An extendable mast, comprising: a first portion of the pull rope on the bottom plate side, the first portion being configured as a cable for connecting to an antenna element, thereby forming an integral antenna.

2. 2. The extension mast according to claim 1, wherein a second portion of the pull rope other than the first portion and connected to the top plate is not configured as the cable.

3. 2. The extension mast according to claim 1, wherein a portion of the cable beyond the first portion and on the antenna element side is configured so as not to be subjected to stress by the pull rope when the pull rope biases the cable.

4. In the linearly extended state, a horizontal beam is provided at a distance from the bottom plate to the top plate to connect the elastic vertical beams to each other, 2. The extension mast according to claim 1, wherein a portion of the cable beyond the first portion and on the antenna element side is disposed on the cross beam.

5. 2. The extension mast according to claim 1, wherein the antenna elements are formed by plating on the surfaces of the elastic longitudinal beams.

6. 2. The extendable mast according to claim 1, wherein at least one splitter is provided midway along the cable, so that the antenna elements exist for a plurality of different frequencies.

7. 2. The extendable mast according to claim 1, wherein the cable is a bundle of a plurality of cables, and the antenna is connected to each of the plurality of cables.

Images